kovz
+1y
York 209 and 210 or Sanden Compressors were used in old cars as A/C compressors. They can be picked up fairly cheap at junkyards and converted to air compressors. I think you can buy them new from a few air ride companies too.
Sure it's safe to roll low, as long as the vehicle is built right. The lower the pressure in the bags, the smoother the ride. I ride with like 10psi in the back bags. The front will vary depending on how your bags are mounted, how much engine weighs, and whether you clear the tires when you turn. I don't roll too low in the front because I have some extreme negative camber since I am using stock spindles. I try to save my tire wear.
I don't run a sway bar because I think it hit my end links for steering. I kinda forget why exactly. But anything is possible. Plenty of bagged vehicles use one. There might be some threads on here about how other people fabricated ways to use a sway bar.