I guess my first recommendation is go with a buggy or truck (2wd) that the hobby shop at the track supports. 4wd may be a little frustrating if you are just starting out as they have more complex drivetrains, usually use mod motors and seem to be a little more apt to breaking.
Trucks are usually a little easier to drive than buggies but either is fine to start.
AE, Losi, Kyosho, and Academy all make competitive products. My guess is AE or Losi will have strong parts support.
Have fun!