AFAIK, you can build a conventional rim brake wheel around a disc-compatible hub with no problems.

Jenson has XT non-disc front hubs in stock if you want one:
http://www.jensonusa.com/store/produ...-Disc+Hub.aspx

And, of course, you could always use a road front hub since the OLD is the same.

I don't see any Shimano non-disc rear hubs on Jenson's web site but a disc compatible hub will work just fine.