I've got 6 packs of these Turnigys from HobbyKing:
http://hobbyking.com/hobbyking/store..._Car_Lipo_Pack
They're great, but you do have to watch the size of them for fitting in your car and the wires are very thick. Maybe the lower C versions are more suitable, think they're thinner and have smaller gauge wire.
The thing with HobbyKing is they seem to wait until there's a large back order (i.e. stock = -200 ) before stocking up, dunno whether it's so they can bulk purchase cheaper or something, but it means it can be a week or so before the ones you want are in stock. Also they go out of stock very quick cos everyone likes a bargin
If you're after a cheap BRCA legal pack dead fast I'd get this though:
http://www.jespares.com/electric-mod...roduct_id=7594