I like MAE Omni. Easy to spray and quick drying. Acrylic enamel with hardener. Also inexpensive. I painted my truck with it and it is doing fine. Nicely resistant to chipping and still can be sanded/polished. Touch ups are easy. I expect it will be fine for 10 or more years. I've even used it for running boards and bed strips. 3 coats are good with this paint.
40+ years ago I painted it with Imron (hardened polyurethane originally created by Du Pont in the early 70s). 2 coats. That stuff is not as easy to spray (it is thicker) but will last a very long time. Also more expensive...especially red colors. But in truth any hard paint will chip easily.
Good luck!
Acrylic enamel with hardener was always my "go-to", still use it for many items. The Acrylic Urethane is just as easy to apply and covers in 2-3 coats, it is a thinner product than the AE but you get used to it pretty quickly.
