Air ride Questions

[lts70]

I am a little confused and was hoping for some advice. I want to install a rear Air bag setup on my 70 SWB. I already have 2.5” drop spindles and 1” drop springs in the front and 5” drop springs in the back. I used the kit from CPP that came with shock re-locaters, drop shocks, and sway bars front and back. The rear springs are way too weak and thus I want to upgrade to Airbags in the rear for when I am hauling stuff in the bed or towing a trailer. I searched the forums and read up on what others recommended. It seems that Slam Specialties RE7’s seem to be the most recommended on the board and ***************** the best place to get them. So I called them up to order my RE7’s and they recommended I use a Dominator bag for $60 a bag or the RE8 for $75 a bag and not the RE7. Also they said it was not a good Idea to run a shrader valve as I had planned and that I needed to go with an Air compressor, tank, and valves to do it right. They said it would cost me $500 to $600 dollars to do this rear system. He said that it would be cheaper to just buy one of their air management systems that gives you air ride all the way around for around $1000 and up. I have absolutely no experience with Air ride systems. I am hoping you guys will chime in and give me some advice. What components should I go with? Should I go with an air ride system over my static drop all together, what would be the pros and cons? If I did go with air on all fours just the basic system, what would be my normal ride height? Would I have to remove my front and rear sway bars?