I've been reading a lot on keeping heat down and found people saying a 6S pack will produce less heat.

I was thinking about getting the SMC Factory Spec 22.2V 3600mAh 60C 6S pack. My Hitec X2 Plus can handle charging a 3600hAh 6S pack at 1C, but I'd have to charge below 1C if I go with the higher spec SMC 4300mAh 6S pack, as the Hitec only does 4A on a single charge channel.

I'm a little worried about the 3600mAh capacity though. If I go 6S I'll be running a Tekin 1350kV 4038 truggy motor instead of the 1700kV, due to the limits of my ESC. I'd like to have this combo geared to have enough power to do a standing backflip (I can't get that driveway video by chainsaw out of my head). I'm not sure what pinion that would take or if that 3600mAh pack will last a good amount of time bashing around a park though. I'm not so worried about the pinion, I've got a 15T here and a 17T and 19T on the way, more worried about how long the 3600mAh pack will last and if I should return the charger and get a higher wattage one if I go this route etc.