If you are going that far, don't forget control arm bushings (upper/lower) for both front and rear. Easiest to do since it'll be all apart.
Some people like to use polyurethane, others prefer rubber. I've used both, I think it comes down to personal preference.

 

Query,
I’ve looked at the moog page, but cannot find how long the springs are on front or back.

 

For the rear CC507 the Free Height is the length out of the box 15.38".
Install on the car is Call the Install Height is 10".

 

Thanks

 

I am a huge fan of air bags. I had them on my daily lowered Avalanche and honestly never touched them. Added like, 8psi to them and only time I ever noticed them was when I would hook up the travel trailer and it wouldn't sink. Schrader valves I stuck next to the fuel filler but I acknowledge you probably don't want to drill new holes. This is just my experience and I wouldn't hesitate to run them in your situation where you need a little extra capacity periodically. Start with the springs of course. May still need a little bit more, though when loaded.