I know you've already bought something by now, but my son is 14 and we just got him a 2000 Yamaha Warrior 350, and he loves it! It is a six gear clutch, gets up to speeds of around 62 mph, and is a hybrid between a sport quad and a utility quad. Great for every terrain except sand. My husband who is 6'2" and 260 pounds drives it with no issues.