Try some neuenergy or flightpower lipos. Specs will not be the same, but the performace will be better. I would say that a flightpower 4900 lipo will easily out perform that 6000 lipo. Not sure about the weight but the mfg website will have that info. Google is your friend...
I think the 4900 packs have been discontinued, Tower no longer has them on thier site, when I was ready to order a new 6s pack I had to settle for a 5000