If your looking for a 4 wheel drive buggy, go to www.4wdrc.com
Team losi makes a good buggy, either the xxx-4 or the xx-4 which is better on rough tracks
Kyosho has the zx-5
Jconcepts has the BJ4 and BJ4 worlds edition.
Tenth technology predator
Academy and a couple other companies make 4 wheelers also!