Sounds like an interesting project. I gotta ask if the frame is rigged up for disks, this would be a superb set-up. 700c wheels, nice cross or touring tires and some disk brakes... but...it's probably not is it? Another thing you can do is find some super skinny 26" mtn. bike rims and run some conti 1.5 cross country's (those are sweet tires!). Years ago both Sun and Mavic made 26" versions of some road rims. Mavic's version was the venerable MA-40 while I don't remember which Sun model was miniaturized. I haven't tried to find a pair of these since somewhere around 1990, but maybe a little searching on the net would be fruitfull. Anyways....you planning on running drop bars or straight bars...? I'm curious where your going with this.