The first thing that I'd recommend getting is the aluminium bottom reinforcing plate,which you'll need if you're going to upgrade the speed side of things. Next,buy the 32dp 57t or 54t spur gear along with a 14t /15t/16t pinion gear, getting all three gives you far more options to keep your heat in check. Your next port of call will be a better set of wheels/tyres, personally I can't help here as I only have a Fury, though I'm sure that there are plenty of other members who can recommend something. This will at least give you a good start along your upgrading route.
After that,you can think about upgrading the motor/esc side of things. Just changing the gearing will make a big difference to the top end of the trucks speed.