it's in stock here...
http://www.valuehobby.com/flysky-gt2.html
they mostly have air stuff if i remember right so you'd probally want to stick to hobby partz for a combo and such...
on the topic of upgrading vs buying new, if you buy new, you have a full roller to pull parts from and build up from both chassis's once i get a little bit of $ i'm planning on picking up an rtr BL and rebuilding my ST pro with that.
the lug