Hmmm.... a little late in coming perhaps. Sorry. Have you bought the truck yet?

Spare parts: I'd get some front and rear suspension arms, and maybe some steering knuckles. BUT, if yer gonna buy spare parts, buy RPM replacement parts. Better plastic than stock. Set of shock shafts perhaps? Just in case any get bent/scratched.

Looks like Amazon has a majority of Venom Lipo packs. Those'll do. Any 3S pack with at least 5000mah and a 30C rating. Get one with a Traxxas connector already installed, if you can. Or solder one on yerself. Amazon has a Imax B6 charger clone for $24. If specs are true, should be a fine charger, but you'll also need to match your battery connectors. I have this charger that I got from HobbyPartz.com. Good charger for $56. Their Gens Ace lipos are a good value.