Full DH setup??

Hey guys.

I've got an Earthwing Supermodel (38") atm and its sick for freeride, but pretty bad for DH. I've got Indy 215's and cult classics on it cuz they're great for sliding. Should I just buy some caliber 44's and a good DH wheel as a DH only deck, or go for a new board aswell. I've heard the evo is a good downhill board, but isnt topmount more stable for DH anyway?? Also, I'm gonna buy this board for downhill and downhill only! So I dont need a DH deck that is good for freeride aswell. Thanks anyone that can help :)