I don't think associated made or makes a dedicated chassis for electric motors, though they are available from other sources. I have a converted RC8-RS and a converted RC8T-FT, both have aftermarket chassis kit conversions that offset the center diff for balance and it gives more room for the battery tray/esc. If and when I decide to do another buggy I'll aim higher than losi or associated and get an x-ray or mugen and try to make it sub 7 pounds.

Out of the box I think the Losi buggy has more going for it: lighter, diffs easier to change/repair, inexpensive smart diffs. Smart diffs are available for the RC8 but you're looking at more than $250 each, where losi smart diffs can be bought for less than $100.