where is a good place to find rc cars and trucks that also sell parts?

For websites here are a few that can help you decide and also have the parts that you'll need. Have fun.
References :
http://www.stormerhobbies.com/
http://www.ampdraw.com/index.php
http://www.amainhobbies.com/

check http://www.virtualvillage.com/hobbies-and-leisure/radio-control.html , they sell loads of parts and accessories at low prices. Delivery is a bit slow, cos they ship from Hong Kong, but it is definitlely worth it if you have time!
References :