Need suggestions/guidance for simple nav/com/obs device

I am looking to create (or buy) a small USB device that will allow me to do the following:- Tune the NAV1 and NAV2, and COMM1 and COMM2 radios- Rotate the Course for NAV1 and OBS for NAV2 VOR- Optional: possibility for expansion to assign more functions.It can be very generic. I don't care about the looks as long as I can understand what's active and easily use it. I saw on the AVSIM store that there is a do-it-yourself selection of knobs, switches, etc. Are these easy to assemble and how difficult are they to setup with FSX? Does anyone have any suggestions for something like this?I don't want to spend a lot of money on this, so I was thinking the build-your-own would be cheaper. Attatched is an idea of the design (using the components from the AVSIM store):http://www.greatergreen.com/temp/simple.tuner.jpgThis doable?Thanks for any help,Sammie