http://forum.ncfjcruisers.com/t2176-airlift-airbags-install
Link is for install info. Yes, I will ship. Yes, bump stop gets cut down, normal pressure is 5 psi when not towing. As you say, the bag acts as the bumpstop. Bags are rated up to 50 psi. 12 to 16 psi is normal range for towing with FJ. I have lost 1 psi (down from 5 psi) in 60 days, they hold pretty tight.