Ahem..... I have to say you are waaaaaaay incorrect mr. frosty on your Powder coating information.
I happen to have first hand knowledge here as its what I do for a living.
There are a xxxx ton of weather durable powders available, there are mixes specifically for durability and UV degradation etc etc.
I was going to recommend to the OP that he have the guy enlist the services of a good knowledgeable powder coater.
There is no way I would choose "paint" over "powder" if I had the option, especially wouldnt choose krylon, even the worst of powder is better that spray bomb.
Please visit my web , as I guess its my resume for ya to look at so, you might get the idea I speak from experience.
pluuuus, I came here to learn smithing and I have learned tons and tons, so I get to pay back with knowledge of what I do in this instance.