if i were you i would not get a brushess till they get better, had a novak 4.5 and sold it and went back to brushed. They have problems but will get better then i will get another on. novak and lrp will fit a 540 mount and can only run off 6 cell.
Synergy N9, OS91SZ-H, Hatori SB18, JR DS8711's, JR G770T, ATG, Arizona Reg.
T-Rex 450SE x2
FlightPower LiPo's all the way.