Ive been looking at ways to lower the weight of the most heaviest part of the truck, the battery. There are 5 different chassis available. anyone have any suggestions?

Just as an update: I ended up with an Outlaw pro II LCG Chassis. It is very well made, sturdy, and really makes the slash 2wd competitive. 
Highly recommended. The chassis is manufactured by thunder tech racing. Their customer service is top notch and they stand behind their products 100%. Check out the link for pictures and info. www.thundertechracing.com/

I hear that minimizing battery weight is super pricey.