If you aren't in need of a high amp range than I used a sabertooth x2 15or so amp controller in my first robot and It was working fine. Some people will tell you about how they can be a pain but I had no problem with it. Also the amount of functions you get. E.G. Reversing and on board mixing work really well. If not rangebox do some really nice 30amp ones that I was really inpressed with. They are definitely worth a look. Not to costly as well.