As for board types, if you're looking to do advanced freeriding (steeps, trees, etc.) I would suggest camber underfoot, with lifted tips. Something with an RCR profile, or whatever they call it. A lot of the Jones boards have this profile, Priors, and I'm sure there are lots of others out there.
Rossignol and Signal also use the Cam/Rock shape you're describing.
I initially was thinking the C-R-C shape would be OK but I notice he has an interest in steeps, trees and bumps and in all those circumstances I'd favor more camber so the R-C-R shape might be a better fit. With that in mind, I really liked the Signal Omni as an all-mountain board. I think the OG would be a step up in terms of big mountain riding, but the Omni would probably be a better fit for a beginner/intermediate rider.