5,000lbs air bags with daystar cradles. Bottom of the bag is not attached let's them move freely when not in use.
This is what I did, too. Although, I used Timber Grove airbags. Why? I found a guy locally selling them cheap. I ran the lines to my license plate bolt holes and put the schrader valves there. I use a bike pump to put air in for the times that I tow or have an extremely heavy load.
Another thing that I do, and is personal preference, is I vacuum the bags up when I am done. I bought a hand operated vacuum pump and suck the bags up until they are collapsed. It means I don't have bump-stops, but I am ok with that. The first time I went offroad with the bags installed and no air in them, I could hear the "slap, slap, slap" as the bags moved in and out of the cradles. It drove me nuts! I found a review on Amazon that mentioned vacuuming the bags and I decided to try it. I have been doing it the last year with no issues.