I was as confused, as you are, by the number of options out there. When asked, a marine mechanic friend and Mainesail both recommended Sea Frost, without hesitation. Any time I called the company to discuss options I always spoke with Cleave, the owner. They have dozens of cooling plate options to choose from and they can modify any of those to fit your specific needs. I chose a standard shape but had them put a bend in it to fit against the curved outer wall of my icebox. The compressor unit isn't much larger than a shoebox so it will fit most anywhere and is very easy to install. Everyone I've spoken with says Sea Frost is very quick responding to service calls.