ESC/motor, you have a ton of options. I'm a Novak guy but Tekin stuff is the smallest out and is adjustable via you PC or laptop. LRP sphere TC is a nice piece (never used one though). The Novak Slyder is an updated GTB with more tuning options, so don't let the name trick you into thinking it's just for drifting. If your on a budget Novak has all there problems fixed with the havoc and it's a good deal at $150.