Agreed with the above, although the AAP-01 is the new full auto GBB darling. Forget electric pistols, they're big, bulky, heavy things with a tiny cylinder volume that need considerable work just to get them up to "barely adequate". The only advantage is that they work just as well (i.e. poorly) all year round.
If you tell us what you're trying to achieve, we might be able to make some suggestions. If it's a sniper secondary for woodland, and you really want full auto, I'd note that the Galaxy G5K MP5K is back in stock at... urgh... BBguns4less, and can be strapped onto a leg panel and forgotten about.