Have you considered having your exixting motor rebuilt? There are companies that specialize in electric motor repair. My windlass motor conks out about every five years. It's in a locker in the bow that gets a lot of salt water spray. I take it to my motor rebuilder (Mamock Motoelectric) and he disassembles it, replaces the windings, bearings and seals, gives it a paint job and returns it to me in a couple days for about $200. He also rebuilds the starter motors on my engines and genny when they need service. His rebuilds are as good as a new unit.