Not sure it's of interest to anyone else, but I just verified that the Hella Rallye 4000 Compact lights fit inside the fog light openings on the Aluminess (Trojan) bumper. Even with the clear acrylic covers installed.
This is good news to me because that's about as protected as expensive lights can get. It also makes them street legal as driving lights here in Washington State (and California, I think), as long as they are wired to only be on when the high beams are on.
I haven't actually wired them up yet. I can tell it will be a bit of a pain to aim them.
Now I just have to figure out how to safely hang some fog lights beneath the bumper so they're street legal. I'm thinking something like this with a protective frame around them.