Need help deciding what to power the E-Revo with!

[R00ST]

so how exactly do the motor turns affect the power delivery? I was thinking the lower the turn, the hotter the motor? (hence the reason a 10l would be more efficient, but probably less power than the 9<8<7l's?)

can all the motors be run on what the controller can handle? (I think the 9920 handles like 18 cells?)

but best efficiency would be on 12 cells right?( or lowest runnable cell count)?