brushless twin force

[jimbob]

well i have seen a few on here and well my 820 motor set-up is just too heavy, nice power but heavy

so any recommendations on a nice set-up...
looking to use 14-16cells (maybe more)
and speeds of around 45-50mph

also what upgrades do i need? probably buggy diffs buy the looks of it, i have heard they fit
cheers