OK, got it done. My Alpha had an additional radiator shroud between the grille and the radiator, directing air from the front into the radiator. It was narrower than the lower grille grate's width, which made it impossible to remove that grate (trust me, I tried!). Ended up removing the entire bumper; really wasn't as difficult as I thought it would be (8 bolts, 4 clips). Here's a shot with that shroud shown, and a couple of slots that I had to cut out (shown in red) for the light bar to fit:
The mounting brackets for each end of the LED lightbar had to be bent and twisted a bit, but then they bolted to the the inside bumper supports on either side (sorry, no pics of the actual mounts). Here's the finished product!:
It's a single row, 30", with 30 5W Cree LEDs. 150W, nearly 15,000 lumens. The nice thing with the single row is that I still left about half of the open area for airflow to the radiator.
I have a single row 50" on the way (should be here any day) for the roofline. I already have G2 mounts, so I'm looking forward to 400W/40,000 lumens of LED lighting!!!