Barring any problems with the figure (which should all be ironed out, fingers crossed), I have no plans to take Rung off sale. So he should still be around when you're ready to grab him! :)
I ordered mine from Robot Kingdom. I live in Australia where Generations figures aren't released, so I'm not sure when they'll be available in the US.
The spoiler has a 5mm peg at the bottom that fits the BH wheeljack. The pipes has a ball socket on the underside that is attached to a ball joint on the vehicle door. The ball joint base from shapeways was designed for first edition wheeljack so it does not fit the BH door - which I had to tool it by cutting off the clip and glue it to the door with epoxy putty.
ratchet and ironhide's present idw bodies seem to be loosely based on a stripped down version wfc soundwave so a head swap and some vehicle mods on those.arcee has a figure coming out later this year directly based on her comic appearance so it will just need to be repainted. prowl i will need to do a little more research though i have an idea using foc jazz with some modifications
here's info on the commissions i do http://www.tfw2005.com/boards/commissioner-listing-feedback/217946-grimlockprime108s-customs.html