setup for crt.5???

[RUSTED]

i m8 get a couple of zippy or rhino lipos

but should i get a medusa 50 mm 1600 kv or medusa 2200 , because i already have a 18 teeth pinion and i want to use it ,

now , should i keep the setup ( shown in the pics above) and use 2 4s in parallel or should i return it like stock and use 1 2150-2200 mah 4s 20c pack ??