[lincpimp]

Well a 6s 5000 lipo should be roughly equivalent to a 4s 8000 lipo. I can get 25-30 mins out of my trakpower 4s setup (4900mah) with an 8xl, so your runtimes may be longer than you think. Plus higher voltage does cut down on the amp spikes, that hekps too. That 6s pack will most likely last a while too, much less stress on it than a 4s setup.