Im guessing you want to do 4WD?
Best bet is to find your near club and go and talk to the people there, see what they are running etc etc...
I would personally recommend a B44, theres a few floating around on here at the moment for good money and its a brilliant car!!! Spares are widely available and a lot of people run them so set-ups are easy to find!
Then theres a fe more things to remember...
1- lipo batteries.. If you buy lipos make sure they are on the homologation list
2- Speedo and motor.. Brushless is your best bet, again make sure the motor is on the list
3- Sticks or steerwheel controller?? This is really down to preference
As i said above, find out where your local club is and pop down to a race meeting and have a browse around and ask some questions
Hope this helps, Tom