Lipos for Brushless

[sleepy23]

I am sure this has been asked several times ragarding other vehicles, sorry, but i need to ask for my application. I am running 2 t4's. One has the novak 5800, the other has the mgm80 and 6s motor. Is there a good lipo pack that i can use with both? if not, what would be the best pack to match up to the mgm/6s combo? and finally, where is the best place to get some lipos?
thanks