I would definitely go for Epoxy resins, for this sort of job... (not just because I hate the stink of polyester) As an afterthought, I would maybe add some fumed silica filler to the "base coat" if you make it yourself. That will stop it being quite so "runny" and make it easier to "paint on" I would probably use a roller for something like this.
Epoxy will be just fine, even if exposed to sunlight/UV, if you get it clearcoated with a good 2-component Urethane (I use 2-comp boat varnish, since I have access to it cheaply, and have my own spray-guns.)
BTW... I got "Sapere Aude" from a very good book called "Reckoning with Risk" by Gerd Gigerenzer... (Penguin books) Well worth a read, I assure you!! and also the inspiration for the second line in my signature
"Sapere Aude"... Dare to KNOW!
The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...
103% of all people do not understand statistics...
Do not adjust our mind, theres a fault in reality :-)