RE: Anyone do electric 1/5 scale?
No, they're Gas (though, MCD's are shipped without engines, so an electric conversion should be pretty simple).
I think the only way to really do 1/6 - 1/5 scale Electric would be to utilize the new Lithium Battery technology. There are plenty of brushless motors out there that will put out power equal, or greater than a gas engine...........the problem is cost.
The Brusless motor, speed control, and batteries could put you out over $1000 if you wanted to have the power, speed and run-time of a Gas car.
I myself have been toying with the idea of doing a 1/6 scale electric 4x4 buggy for quite some time. I have most of the planning done, now it's just gathering the money and parts.
Electric is nice because of the lack of noise, smell, and clean up.