I'm thinking of making a move to a disc frame - the Gunnar Hyper XX. Right now I've got a 105 group on my road bike - all I'd need is a mechanical disc brake like the SRAM Avid BB7 correct and disc wheels to make this move work right?

105 levers should work fine with disc brakes.

You need something like bb7R - you need either short pull brakes or a travel agent or something similar or you'll have a lot of trouble trying to get your brakes adjusted.

You want TRP Spyres, TRP Hy-Rd, or Juin R1's

My Raleigh Tamland 1 came with 105s and TRP Spyres and worked well. When I changed to TRP Hy/Rd it worked better.

You just need disc brakes made for a road lever. So BB5/BB7 road, TRP Spyre etc and yup new wheels.