I tow a 1981 trillium
5500 with a 1995 Lumina APV that's also a 17 footer.
I weigh in just under the 3500# limit, and used to use air shocks, I got rid of the air shocks because the factory ones were $400.00 pr., and the afternmarket ones , while only $100.00 pr. ,(If you watch ebay)didn't last over 2 years each . I went instead to overloader shocks, the kind with the spring over the shock, and while it rides a bit stiffer when not towing, It's excellent when I am. I also have air bag inserts in my springs (air-lift) which were installed back when I had air shocks, these are a great add-on.
I use a single side anti-sway bar, mounted between the trailer tongue and the stinger, and it has worked fine, even with a blow-out on the trailer, no sway, no jerks, nothing, just pulled over and changed the tire.
It also cuts down on sway caused by transports passing.