fond of promatch racing myself. the new IP lipos he is stocking are reasonably priced and have a 1 year warranty. I got some of the 7200mah 80Cs myself. Heard good things about SMCs as well with price to performance. I think there 6500s are pretty cheap right now, though dependent on what works for you of course.
I keep going back and forth between running a shorty and this big packs I have. Like the feel of the shorty but the big pack wasn't exactly off pace either.