I finished this up a few weeks ago but wanted to close the loop for anyone following. I spent some time taking the air saw apart, polishing up the piston, matching the air transfer ports, seals, etc. and its actually working a lot better.
I was able to get the job done pretty quickly after that. The blades worked much better than the jigsaw that I started with. I could correct the cut line easier and if I bound it up the saw just stops where the jigsaw was jumping all over and could have scratched the paint.
I started with a .125" pilot hole, went to + .5" on all four corners with a Uni-bit then used the saw. A die grinder with a bur and band file were used to clean up and even the cut lines out. I found the template for the Rigid D2's to be spot on width wise but needed a little extra top and bottom. Overall I'm very happy with the fit and only a very small nick where the jigsaw blade jumped out of the hole.
I painted all the bare metal with a self-etching primer and then a zinc coat paint before installing the lights.
The rear bumper has a slight curve and the surface mount LED's come with a rubber gasket so it does allow for a bit of vertical adjustment but also a small gap for dirt to settle into. I may add a bead of silicone and foam tape to get rid of the gap. Its just cosmetic.