Someone here (actually I think it might have been you A.I.I.) posted up pics of a Raptor with a custom roll cage welded in. They're here on the site somewhere if you do a search.
I agree with A.I.I. though, a bolt-on roll cage is about as useful as a screen door on a submarine!
If you want a functional roll cage, it needs to be welded to the frame. Haven't heard anything about the seats you're describing as of yet, but with the newness and popularity of the Raptor, new mods/products are coming out pretty regularly these days.