Yea..I have a 4s balance adapter so I can charge in series so that shouldn't be a problem.
I have decided to go with 4s. Since this truck is going to be close to the same weight as a 1/8th e-buggy I think 4s will be required to give it enough power.
The speedpassion silver arrow motor will be sold.
After much research I have found an inexpensive motor which I think will give this thing plenty of power. I don't want to spend a ton of money on the electronics because well.. this thing will be beaten and I don't want to feel guilty when I take this monster to the skate park..or jump it off a 20ft ledge,etc.
Anyway.. I believe I will be using this motor along with two 2s batteries. Looks like a great deal for $50
http://www.hobbypartz.com/96m802-4074-2150kv.html
I just hope 2150kv is enough.