Waxes ,cleaners and polish are different chemical make ups, each do a specific job for the gelcoat.

Cleaners should be used first to remove stains, pollution build up, scum, etc.
Any of the light compounds should do a good job cleaning the gelcoat with a buffer or hand scrubbing.

Meguiars heavy duty gel coat cleaner is a good one.
http://www.jamestowndistributo...mover

Polish should be used next, it will remove almost all of the little swirl and scratch marks from the gel left behind from the cleaning compound and leave a glossy, glass like finish

Meguiars Polish
http://www.westmarine.com/1/1/....html

Wax goes on last to protect and seal the glossy finish the polish put on. A good High caranuba wax will protect the gel from everyday pollution, make scum lines easier to remove after a day on the water , etc.

Collonite heavy Duty Fleetwax is one of the best
http://www.waxbytes.com/marine.html


Not many of the combo wax/cleaners will work well as the cleaner part is usually a compound type to remove stains, etc while the wax is their to protect, kind of like an oxymoron, trying to remove dirt/stains and leave a coat of wax at the same time. Something isn't going to work right.

To really do it right, all 3 should be a separate step.