Which KB piston is it? Are you looking for a Hydraulic cam or something more exotic? Do you want lope or smooth? Do you have a HP number or ET goal? As AJ has pointed out tire size and gear ratio will play a large part. Your heads and intake will support a large cam which will need some compression for optimum performance.
If you are going to buy a cam I like to suggest a custom grind, then you can get exactly what you want and it really doesn't cost much more. If you want to save a few $$ run the MP cam, it's a good grind even if it's a bit old school ( I do think they made two versions though one on 114 degrees separation and one on 108 so check which one it is).
Garth