Well witha 12/12 at least we know he wants- speed. I have put together a few wm 40 size P-51s with 61fx's in them and they seemed to have run best on 11/7 or 8 apc. I would stay in the 11's and start with an 11/8 or 9 sport prop. The average hobbystore does not stock usually what you need and may need to go on line.
Don't forget your at 2000ft elevation. You have around a 6% overall power loss and nothing you can do about it. Experiment in the 11's.
http://www.apcprop.com/