Here is the low setting of my 2-part "Adoramus te, Christe" ("We adore Thee, O Christ"). Pretty straightforward, easy, and short.

Note: Following MJO's suggestion, I've replaced the score with one that incorporates his suggested placement of the syllable "-ly" in the upper part.

Beautiful, Chuck!
I suggest moving the first bass '-ly', of 'holy', to the second beat,
away from the strong first beat which would inherit an extension of 'ho-'.

Look at the German bicinia, which were designed for just such needs. The Rhau ones in Latin will be more useful that Othmayr's German chorales. Several in the Rhau print are canons at the unison. They're mostly too high as-is, but can be transposed downwards.

Here is one I set up for my schola of baritones:

Here is a Compline I put together for a choir of baritones and basses in 2-parts. If they are seminarians, then this would be a fitting end of day office. if the 1st Ps. 134 is too high, pitch it down a minor 3rd. It will still work. I have a complete plainsong Compline in realized monody for basses, if you are desperate.
jefe

Osborn, I have no excuse. I was using some instrumental instinct here with Ps. 134 serving as an introit or fanfare with the imagery more important than the perfunctory Gregorian or strict Psalm Tone. The Old English Psalm was put in there optionally (there are 2 choices for Ps. 4) for some variety, unlike the Psalm Tones of old, which had stricter rules. I'm mentoring a start-up Compline Choir a couple hours away from our place, and am feeding them some easy, already packaged Complines, as above, with lots of chant to get their Compline ball rolling before moving to the more complex. My other compositional and arranging technique is to pump the Mystical. After about 100 Complines with our groups, one thing I've found is the singers and listeners who live in the now, weary of the same sound over and over again. Chant, well done, still sounds sweet to the ear, but pales to grey tones in the whiz-bang culture we live in. We've done many chant-only Complines and I love it, but the singers, who may be younger (Thanks be to God) and more connected with pop culture are there to get their fill from their perspective too. This is one of the true successes of St. Marks/Seattle: they keep it interesting. Folding harmonized pieces into stretches of chant, and wallowing through contrasting English and Latin has a great and other worldly effect, especially if you are a good seamstress. It's like going from black and white to technicolor in one pop. But, it's the contrast that keeps it up to date without bowing to the lowest common denominator. Our Compline program has grown to be the best local outreach in our small town. One wag called it, "The best non-alcoholic happy half hour in town." They don't know as much as you do, so what they don't know won't hurt them.