I do know that in Clinton, Illinois - The Dewitt County Sheriff office has TWO Humvees that were Government donated to them - both have the fast back and hard tops with turret covers. Kevlar doors. I lived there for years and these things just sit there rotting away. Perhaps a fellow could make the Sheriff office an offer for both of them - and get trucks, tops...and all. I imagine the repair and storage on them has exceeded their worth.
Probably get two complete trucks for the cost of kitting up an aftermarket or buying up a complete used top assembly.