Yeah, I have ordered from Impakt and have had no issues with them.
Remeber though, different batteries brands use different balancing plugs, so when you order the charger make sure to order different balancing plugs for the charger if the the battery packs you buy don't use hyperion taps

You could also buy from rclipos.com
They have the hyperion charger for $140 and shipping is free. They also stock elite lipos, which IMO are very good bang for the buck. 4800mAh 2s elite lipo for $71, 3s is $106, 4s is $136 and 5s is $169. These lipos aren't talked about a lot and i'm not sure why. I have 2 of the 2s elite lipos and so far they are awesome.
Well, good luck with the shopping :)

Thanks for the info those are good prices