Good choice. You won't regret it.
You're going to need TWO Lipos. OR one 4S Lipo. This is your first RC, right? So there's no reason that you couldn't just get one (or two!)
4S packs, if you've got the scratch. That way, you'd only have one pack to charge, to run your car, instead of two 2S packs. If you got two 2S packs, you'd have to charge one, then charge the other, which takes 30-75min
each depending on battery's charge state. You could get a charger with dual ports, but they're more money than a single port charger.
Again, this is your first car, right? An 8th scale buggy usually uses a lower-RPM-per-volt (kv) motor, but higher-voltage batteries to get their speed. 4S is the car's max, for racing. You might want to consider getting a 3S Lipo to use while you learn to drive that fast buggy, and get a 4S later, when you've gotten to be a good driver and not hit stuff. 4S is a LOT of power. Just giving you some things to consider in making your choice.
So, if you decide to go with a single pack instead of double-pack lipo, I would get the Thunder AC680 charger at HobbyPartz.com . Less than $70 (I think it's on sale for $50 right now) and can charge single pack lipos up to 6S at 80W. That is probably more than the cheapest dual-port AC-powered charger you'll find, and the dual port
splits that total power between the two ports, so you'd only be charging at 40Watts per pack, if you went dual-pack.
http://www.hobbypartz.com/73p-ac680-accharger.html
HEY! They've got 3S packs on sale for $50!
http://www.hobbypartz.com/98p-40c-50...se-direct.html
Here's a 4S
http://www.hobbypartz.com/98p-40c-50...se-direct.html
Whatever battery you choose (and I do recommend those two above) I highly suggest staying with lipos rated 40C minimum. That rating is indicative of how much current (amps) the pack can supply. If a motor system tries to draw more than the pack can comfortably deliver, the pack can heat up. A little is ok, but too hot, and they can puff, or swell. In which case, the battery is suspect. So don't be tempted by the less expensive packs that are only 25C.
NOTE that you will have to change the battery connector to match the Deans connector on the car. If you don't know how to solder, get someone to do it for you.