battery for rustler?

[rcsammy]

hopefully what im doing wont push the pack/system too hard, i just want to gear it for around 40+ mph, hopefully wheelies and hopefully it will be able to run the whole pack without overheating(i guess motors and ESCs temps level out during a run not just keep going up?)

also should i get the:
truerc 3S2P 8000mah 10C $110
truerc 3S2P 8000mah 15C $150
will 5C make much difference?($40 difference?)

also both packs are sold out on the truerc website, any idea how long they take to come back instock?