Ok, so I have given up finding an OEM light that fits the new ARB bumper. I can buy the lights from ARB, but they're fairly expensive, and I have heard about connector issues as well. To combat that, I decided to just put in some 2.5"x6.5" oval LED lights. I got a pair from Amazon or Ebay for $20 IIRC. They came with the wiring pigtails, mounting grommets, and of course, the lights. I made a template on paper via Solidworks, and cut it out and traced the oval onto my bumper with a paint pen, centered on the original openings.
Then I busted out the plasma cutter and followed my lines. This one needed just a little tap to knock it out. The other side fell out on it's own as I finished the cut.
All of the back-side light mounting bracket came out with the pieces I cut, so I only had to clean up the opening a little with a die grinder and some sandpaper, shoot a little semi-gloss black on it to keep the rust at bay, and put in the lights.
I'll get them wired up over the next couple of nights. I now have a much more finished looking ARB bumper, and sealed lights that I can replace for cheap almost anywhere I might be.