Two wired hand held controls, each with about six foot cords. I found some Bulgin watertight connectors at Allied Electronics that are really good. The connectors sit in the anchor well and a winch pocket. I can't say enough good things about these Bulgin connectors. Having gone through so many "Marine Grade" connectors sold at boating stores that quickly corroded away to useless. The screw on caps make a very good seal.

Your switch idea sounds fine as long as you are comfortable reaching inside to operate the windlass. For such an important function I would not go without some kind if backup.