Can anyone tell me the max kv motor i can run with my stock 45amp esc, i'm running 2-(2s) 5000mah 50c lipos in series so (4s)?? Sorry, i'm still catching up on lipo speak. Should i get an inrunner/outrunner, any particular brand?? Also looking for prop advice, whats the best upgrade, 'bang for the buck', size prop i can use with the stock shaft, and where can i get them, thanks.