Hi. You need 2s lipo packs in the correct configuration either stick or saddle to suit your car. The car will be fine with brushless don't worry about that.
You can go with some cheaper 5000 30c type packs that should do you fine. Amain or any of the big online retailers have a good range. IMHO avoid the hobbyking turnigy packs as I've had issues with them. Lots of people say they are fine but they weren't for me. For you application id say they'll be fine but I just don't like them.
Never charge a lipo on anything other than a proper lipo charger for many reasons which I won't go into here. There are plenty of cost effective lipo chargers on the market too.
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