for answering the actuall question posted here i would say either gt2 or firestorm but if you go with the gt2 get the kit otherwise you will be throwing away all of the electronic garbage in the rtr gt2.
also make sure it has the updated hex screws beleive me you dont want the recalled ones.
for the cheaper way the firestorm is a good reliable truck that is pretty well balenced and tough, as far as fast it does have a .18 in it (not a really good one though) but for dirt its not too bad.