Just so it's said, I don't think there are enough grey pieces in the world to build his primary weapon, so don't hold your breath.
The head was something I'd been pondering for quite some time, once I saw what MAKUTA'S KANOHI looked like. After finally getting my hands on one, I discovered that the design wasn't at all as easy as I thought it would be. Eventually I settled on a design that roughly approximates the arced shape of the DSG helmet, but the consruction doesn't allow for the KANOHI to be attached to a TOA head...which in turn meant that I had to get very creative with some filler pieces so the head wouldn't be empty.
The three silver pieces (forehead and both shoulders) are meant to represent the three Imperial symbols on the DSG uniform, and the two light-grey half-bushings in the pelvis are as close as I could get to a shiny silver belt-buckle.
Finally, I flipped the torso around so the rear gear-hoop was incorporated into the chest blast-armor. The armor could look a little better if I hadn't done that, but then the gear-hoop would be sticking out of the back.