Yeah, if you want racing stuff, those are the places to go. You could also add Sheldon's Hobbies for NorCal and Speedtech does retail out of their place for the Socal area as well. Don't waste your time with the Hobby People chain or most of the Hobbytown stores. They sell RC stuff, just not a whole lot of serious racer stuff.
I'd recommend going by Speedworld or SoCal just to check out the racing as well. They're both two of the nicest, most competitive tracks in the country.
Here are some links for you:
SoCal Raceway: www.socalrc.com