Related pics:
The 2x12 board config (a 4 ft section with a 2ft section nailed on top at the end, so I can step up in increments), setting about where I want to nail them down at. Plus the hook attachment stuff mentioned above:
All the rest of my tools and install-related junk currently sitting in the front. All I've managed to install so far is the pitpal cabinet on the right and a pair of front D-rings closer to the car.
This worked out well - a set of RaceRamps made for trailer doors with notch cutouts. I got everything down at a low enough angle to allow for a future splitter: