I chose to build my bike out of Nashbar's cyclocross frame and carbon fork. The carbon fork has disc brake tabs. I built this after wearing out a dept store mtb, or as I was wearing it out.

I decided to build it because I couldn't find everything I wanted in an out of the box bike.

Wheels are 29'r Sun Ringle Highriders. It's a mtb wheelset in 700c size. The brake is an Avid BB7 mechanical on front (roadbike version). Tires are Panaracer Pasela GT, kevlar belted and kevlar beads 700c x 32 with Mr. Tuffy tire liners.

Handlebars: Bar One Midge, a mild drop bar in mtb tube diameter Shimano barend shifters, Sora delrailleurs.

I wish now, I had done this sooner. The difference is amazing. Headwinds are not the devil they were on the mtb.

You could take a rigid mtb frame and build out a commuter with drop bars and road drive train.

My riding environment/road conditions are as bad as anyones. Broken glass and new potholes dictated my choice of wheels and tires. The wheel choice mandated a cyclocross frame. Disc brake on front narrowed choice of fork to the one sold by Nashbar. I am not afraid to take off road detours when necessary.

I built this after commuting every day for 18 months. I even put the cyclocross fork on the mtb for the last few months. It handled very well. It was the first part I bought. came up on sale one day.