The General Finishes High Performance gets good reviews. I've used use it (recently, no long term experience) and it goes on very nicely, I sprayed it with a 1.8mm nozzle on a Fuji HVLP setup. Like Jim said, anything you use will need maintenance eventually but some of the better products go a long while. I've read several articles and opinions about the GF Exterior 450, though I've never tried it. That's the finish that will likely be on my next outdoor piece.
I long for the days when Coke was a cola and a joint was a bad place to be (Merle Haggard; 1939-2016)