I don't care what you do, or how you do it. If it's steel it's gonna rust. Period. Best you can do is hope to keep the rust at bay for a while.
You can have it dipped, and stripped clean, then dunk it in a vat of POR-15,
coating it inside and out. then paint it with whatever coating you want to.
Eventually, the rust monster will get to it.
If you are over 30, and sandblast it to clean metal. Epoxy prime it, and paint it with a good qualty enamel, or urethane. It should out last you.
Eventually there will be a few rust spots pop up. but it will remain structurally sound for longer that you will be able to use it.