One thing I would love for a pep is Greymon's hard skull shell and horns. I am making an animatronic head for a full tokukatsu style Digimon prosthetic suit. With a pep of the skull I would have a perfect substructure for the animatronic system.
I am going to make it close to the Greymon from season one and the first movie, but make some of the proportions more realistic like in the gut and possibly digitigrade stilts.
Oh I just thought of one that I don't think is out there yet. The Blue Beetle!
Sections of the head would have to be sculpted as a prosthetic, but the rest could be peped and the black parts could be cast out of black latex or silicone.
I have looked everywhere possible on the web and have yet to find anything on a costume build for Thor's outfit in the Avengers when they're on the helicarrier he has no cape. It would be so awesome to get a pep file on that down dressed style armor