forgot to mention, if you DO find the JGs in stock, there are 2 different revisions. the old one which has a tm compatible hopup more than likely not a nylon fiber body and the new one with a proprietary hopup and a nylon fiber body.
The new hopup is actually pretty good, but plastic. I don't think there's an aftermarket replacement for it yet, so if you break it you'll be in for a world of shit.
The good news is that apparently all you need to do to convert it to the TM style is find the TM style magwell and hop up unit and it will work. I haven't put my hands on the new one yet so I can't tell you if that's true or not. according to the people who I've asked and have tried it, it works.
I futz with V2s, V3s and V6s. I could be wrong... but probably, most likely not, as far as I know.