I would go with the Unicomp, personally. While he would likely be perfectly comfortable with getting a converter for an older Model M, the simplicity and ease of use of USB on the new Customizers is hard to beat. You could still get the 101, though, if you want the old school, no-windows key version. I'm fresh out of bolt modded 1391401's, or I'd offer up one of those.
But I do like this idea...too bad there isn't any sort of wireless converter out there that is cost effective.