If you go Maxamps, I would suggest against the packs with 2100mah cells. Many airplane guys liked the performance of them, but after about 30 cycles the packs had a dramatic drop in performance.
Another site for Lipos is this one:
http://www.commonsenserc.com/index.php?cPath=37 Their prices are good, and as far as I have heard their packs aren't bad at all.
I myself am particularly interested in these packs (for paralleling and putting in series):
http://www.commonsenserc.com/index.php?cPath=37_35
SH Z-Car, Custom Crawler, 8s Savage,
12s XTM XLB 1/7 buggy,
4wd 4-link rear/IFS Pro4 truck,
Custom Hyper 10 Short Course,
Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz