I'm saying specifically 3300mAh NiMH, not NiMH in general. Like, a 3600mAh NiMH will give a LOT more power I've found.
The site you linked has a pretty good price, but that kind of charger is next to useless. Spend the cash and get a good RC charger like a TLP or Duratrax, it will give your batteries a longer life span and save you money in the long run. I use a
Duratrax Piranha Digital Peak, you can probably find one for under $80.
Check this link:
http://www.cheapbatterypacks.com/mai...r=20&model=197
It's pretty simple, but keep in mind you probably don't need your pack upgraded; it'll give you negligible performance gains for the price.