Okay......3300 Mah (Mili Amp) NiMh (Nickel Metal Hydride) is what I recommend.
3300s will give the car a lot of punch, and good run time. Don't try to save a few bucks by getting 1500s. You'll be bored pretty quickly.
NiMh batts are also maintenance free. NiCads (Nickle Cadmium) batteries have to be cycled regularly.