I'm far from an expert but I'll throw in my two cents as I just installed mine in a very similar arrangement last weekend.
-I went with the Mono panels, was led to believe they are better than Poly
-get some mc4 connectors, you'll want them to shorten your cables to the exact length you need. Easy to install, ideally you'd want the crimpers but I got by without them.
-I went with their brackets but if doing it again I'd probably build my own. The brackets are kind of cheesy and look pretty tough to remove the panels if you need to.