build a gmaxx and i need help

[suicideneil]

Which esc were you using again? If its the MMM2200kv combo, then it will be alot of power, but also lots of fun. 4s is good for general bashing, 6s for speed runs, but I have found 5s lipo to be the perfect mix of power and speed.

The lipos you linked to would be fine, or a combination of a 2s and 3s 30c 5000mah to get 5s total (truck wont be unbalanced as the lipos are so light).

All depends on what you plan to do with the truck, and how much room you have to use it in- a tight street woudl be better with 4s, but a big open field or gravel pit would be more fun with 5 or 6s...