The postbits are very out there.

It's a very nice skin. That could very well be custom, as none of it seems that hard to do.
I'm also not sure of the limitations of vBulletin... I'm not sure if you can code the entire postbit in divs, but I don't see why not. I used divs inside of the message area to place the signatures.
But sorry.. I've never seen a skin like that for vB. Wouldn't be too hard to make though.