I didn't read any of the replies, so sorry if this is a repeat.
Full sized bodies, you can't beat the Superbolt in weight for the price. It's not high quality (the feedneck is held in with a set screw; I mean, really), but it sure is light.
If you're handy with tools, you could always dremel down a stock body ($25-30 in the BST) to a tube, and whiddle away at the backblock some. That would be my recommended way to go.
For this, go with the best AT. The CCM AT. It isn't cheap for such a small part, but it'll last you forever.
I love the feel and stroke of the Shocktech sliders. That and they have a nice looking snatch grip. With the sliders, you will wither have to modify your trigger plate, or buy one of Pump's pre-mod'd ones, in order for the AT to work.
I would honestly say skip the AT. Just work on developing your rhythm. Pump, shoot. Pump, shoot. Snipers are smooth enough that it won't be an issue. After one full season you'll be able to hit 5 or 6 bps with a good rhythm down pat.
The Inflicted (MCB) - "Anyone find it amusing how as spool valve guns have progressed they've just gotten closer and closer to the Automag? "
"But if you don't want to serve the Lord, you must choose for yourselves today whom you will serve... As for me and my family, we will serve the Lord."
~PROUD member of the NRA~