definitely go sensored... all higher end ESC's are sensored if they are worth a darn. Novak Havoc 3S is for 540 and 550 motors but limited to 27T for brushless 540 which is the size motor you would use in a buggy. The Havoc Pro SC is for 550 motors only which are only allowed in Short Course (SC) trucks, so don't go there. The tekin RS Brushed/brushless is a great ESC for mod racing at about $160. This is one you can program to have reverse or not and it will handle any motor you put in the buggy. The Novak GTB 2 is a great sensored option as well for about $100 and has a 3.5T motor limit which is way too HOT for 2wd buggy, so plenty of room for motor swaps, etc.