I'm going to use Durabak. About $300 total. My reasons: 1) it goes on with a roller, and if it gets messed up later with scratches or tears I can roller on more. 2) doesn't need as much prep work as paint 3) it won't show as many flaws as a smooth paint. 4) it can be painted so I can slap on a different color if I want later.
I was concerned about it collecting a lot of dirt and dust, but it gets that now in dusty, dirty Los Angeles. I'll just take a power washer and long handled brush to it when I want it clean.