Looking for new Mini

Well, I'm going to order the CRT.5 Pro.

Will be using a MM esc with the 5700 motor (for starters) and 7.4v lipo's.

I'm going to buy the following :
RCM's motor mount
12T pinion (maybe also 14T ?)
bore reducer to 1/8" for the CS motor
heatsink wiht fan for CS motor
fan for the esc
RCM's battery tray/box (or what other options I have ?)

Will those fans take away power from the batt. ?
Do I need and external BEC ?

I'm I forgetting something ?