I went with the Firestone Ride-Rites. Tied both air line together in a common fill valve at the back bumper and use a bike pump to air them up. They don't need much air so a couple of pumps and I'm good to go. There are two style for the Firestone, one with a gooseneck/5th wheel hitch and one without. So get the right one. Run about 8# (5# min) when empty and pump it up to 18# before I set the trailer on it.
We were about a 1/4" off the overload springs and so air bags gave me back that clearance to the overloads and much improved the ride.