MGM controller do I go for amperage or cell count??

[Finnster]

Well I'm always looking for more info so I can make better predictions, but they are always just that.

Check out ZPB's Revo thread in here. He is using a 1700kv Neu/7S A123, albiet a smaller 1512. He's was only pulling a max of 80A, but on a lighter Maxx. In on 1P, the lighter Revo is getting a bit more v-drop. If you stick to 2P, you should be good upto ~140A, so I think the 1700kv 1515 would be a monster, but very doable, esp on a 160A ESC (I'm upgrading my prediction ;) ).

I have no idea if the tranny will handle it (not my dept.) but the motor and batts should give you a kickass setup.