Aircraft stripper from PepBoys works well. Comes in Aerosol and gel/liquid form. I found the gel to work slightly better. Make sure you get some thick rubber gloves and wear long sleeves/pants. It is a very messy experience and it hurts to get this stuff on your skin. I found plastic scrapers and nylon bristle brushes help scrub/scrape the crap off the finish. Depending on what type of finish you have it may take a few applications to get it down to the bare metal. I did a set of '94 Mustang wheels that actually took me about 4-5 applications go get the thick powdercoat off.

As far as polishing goes I have no experience with it. Perhaps someone else can chime in...but all I can tell you is look forward to putting in a lot of hours to get it right (particularly if these are cast wheels without a smooth surface).

Best of luck!