Find the local homeschool community. Recruit there. Make sure they know it is an "adult program." I would also invite the children in grade 6 and higher. Homeschool families are larger than most and parents are keen to have a music program for their kids especially if it involves Latin and is free. Often they play piano and can read some music.

CharlesSA, welcome to the forum. Since your pastor has made this decision and come to you with this request, you might ask him to initially take the point on this matter by asking interested parishioners to see you after mass. It seems reasonable that he must be aware of a desire among the congregation for the EF, so perhaps at first you can make use of his knowledge of the congregation and their needs and desires. Canadash has suggested a great resource for all of us interested in forming a schola from scratch. Please let us know how you are doing as you go forward, and break a leg.

Thanks, JQ, I was in the middle of this when your correct observation popped up.
Samuel, I think we're addressing different objectives that may/may not be part of CharlesSA's concerns. As I understand it the EF will be an addition to the schedule. Without any further information, it's difficult to project that the new EF could possibly be SHM fairly early in any timeline. So, if it will be a Lecta/4 hymn, well the language issue is still moot.
But as JQ said, my interest was aimed toward Charles "flushing out" prospects at all the 2 parishes. I would not advise the exclusive use of Latin for that initial purpose.

PIPs are people in pews. There's no reason not to start tomorrow if you have one good singer. Building a larger schola depends a lot on geography and the time: some music majors who hold down a Sunday morning gig might still be interested in exploring a more fulfilling repertory at night.

Please try to interpret other people's choice of vocabulary in as charitable a way as you can muster.

Your laudable attitude toward the Mass is not charity: it is reverence.

As soon as we can invent a short word for "music performance opportunity" (or "performance commitment"), it'll come in handy.

Of course- after all, we young folks can only communicate in monosyllabic words, like "Gradual", "Antiphon," "Evensong," "Magnificat," "Allelluia," and "Schola Cantorum."

Getting back to helping the OP if we may...

Like some above said, get the message to the congregation somehow because there is likely a few with good musical experience who are not in the choir because reasons.

Also, see if you can recruit from local colleges. Strike up a friendship with the vocal instructors, offer it as educational/resume experience (maybe even see if it could count as ensemble credit), etc. You can dominate the universe if can get a handful of young whippersnappers. :)

Scott W's advice is spot on. You are in an area (greater Kansas City metro) with several colleges and universities with good vocal departments. If you are able to recruit one or two really good singers (and they find it fulfilling), their enthusiasm can be infectious in helping recruit from their friends and acquaintances. You may even find an occasional faculty member who isn't already committed somewhere. High school choral scholars (especially from home-school families) can be another avenue. If they are really good singers (or show potential), get them involved. I would suggest setting guidelines and expectations (regarding attendance at rehearsals and services, studying music at home, decorum, dress-code, etc.) before the first rehearsal. It's much easier to begin with regulations than to try to announce and enforce them later. Prayers and very best wishes for your endeavor. Go for it.

Sorry, Richard C (and thank you SD for your contribution here and elsewhere, always valuable,) but I'm gonna defend my Richmond friend's innocent nomenclature use for the benign non-issue it is, and question the necessity for pomposity digressions that, frankly, make us look like snobs.
Do the math, Jackson. Anyone who takes the time to post and read and help others in this forum is prima facie not someone who shows up 2 minutes before Mass, has a beer during the homily, and then glibly cashes in a paycheck. Let's show some charity to our colleagues whilst we're reverencing the Divine Liturgy and try not to discern "intent" or disrespect before all else.
If you're so put off by the term gig, try thinking of the ratio of great DM's like Mr. Mix who spend hours preparing for the efficacy and beauty of each Mass for which he serves, to the number of clerics who literally do walk into the sacristy 1 minute before Mass expecting every detail and minutiae of physical preparation to be in place so that all he has to do is suit up. Think of a lector who can't be bothered to reference the pronunciation of Massah and Meribah, but thunder like a Barrymore, fracture clauses, and take five minutes for one small scriptural paragraph. Think of a deacon who upon first glance of the Universal Prayer (during THE MASS) gets to the intentions for named decendents, and utters "Ee-stay-ban Care-ah-millow" when what is written is "Esteban Caramillo." Those sorts of folk treat the Mass as a gig.
And we, we musicians who have given a rip for many decades, endure this sort of pathetic atmosphere forever and never say a thing, 'cause we're "the help" when it comes down to it.
So who's really getting the "gig?"
Us frogs. And we are disappearing because we can't see the forest for the trees anymore, and everyone from "Father" to some indignant usher to a PIP who complains the d*mn organ's too loud while he's shouting at the top of his lungs to his wife about his gout during the recessionaly hymn.
Off the soapbox if we can stay off the pedestal.

It's interesting to see how many nautical uses there are of 'gig'. The origin of the musical sense is obscure, but I seriously doubt it's of pagan origin. Around here it is an engagement with expectations of professionalism and I think it connotes higher standards than 'church job' as well as real money ;-) So, would that all whose role is to serve worshipers approached their tasks with the same seriousness.

The origin of "gig" seems to be as a colloquialism for "engagement" that arose in the 1920s amongst professional jazz musicians.

Richard Mix - yes, theoretically, the priest could start it now and have it every week, because I'm capable of doing all of the chants by myself, and I could also add in a little organ music at some places. I think he is waiting for Septuagesima to start the Latin Mass. He already has a "timeline" in place of when and how he is starting the EF Mass. It's just that I would prefer not to do that myself every week, and although I would be fine with just a small schola to start out, I also would like to recruit choir members so we can sing some polyphony as well.

Scott_W and SamuelDorlaque - That is a very interesting idea to recruit from the colleges in the area! There are I think 5 colleges within 15 miles from the church, and 2 of them are Catholic as well. I think all but one of those 5, though, are nearly 20 minutes' drive away, which might be a drawback. Also, there may be shortages in the summer if the only singers I can find are from colleges, but that is a good idea - thank you both for your comments on that.

CharlesW - thank you for the suggestion. I will ask him to direct me to some of the people interested in the EF to see if they have suggestions for choir members.