unless you already have nihm cells i personally wouldn't spend any money on nihm cells or a charger( i made this mistake when i got my sv) after a little while you just want to keep going faster, at least that's what happened to me, the cost of lipo really isn't that much greater than the cost of nihm, once you get over the whole what if my lipo cells blow up they are pretty much just like using a nihm cell, the charger takes care of proper charging, a balacer requires no thinking, lipo run cooloer and charge cooler, not to mention supply power in a different way than nihm that provides more punch and longer run times, the biggest cost of lipo that isn't associated with nihm is the balancer( 30 bucks) and a lipo protect if you esc doesnt have one, which unless mine was hiding somewhere my stock sc esc does not have a lipo protect, you can get one for 20 bucks and they are really easy to install, remove esc plug from reciever, plug in esc to lipo protect, plug lipo protect into reciever, and solder a + and - lead to the battery connectors, takes like two min, so for 50 more bucks you are going to have a product that you will continue to use with reliability and you will be on the cutting edge of battery technology.

to make a long story short, skip nihm and just get lipo

ps. i dont have the charger riverrat mentions so that's why i got a seperate balancer. this charger sounds amazing, ac/dc is always a nice feature not to mention the balancer is built in, i paid 55 for my charger and 30 for the balancer, 1-4 cell lipo, ac\dc compatable,i dont know how much that charger is or what it is capable of but it does sound awesome