Were you looking to go Lipo or NiMh? If you haven't done so already, take a look at this thread:
http://www.rc-monster.com/forum/showthread.php?t=17544
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