http://www.harborfreight.com/power-tools/polishers/6-inch-compact-palm-polisher-90219.html
This is the buffer that I used and it does a pretty great job for 18 bucks but it broke during the polishing of the glass. Went to get a new one and apparently they stopped making it and now have this buffer in stores unless you get lucky.
http://www.harborfreight.com/power-tools/polishers/6-compact-palm-polisher-69487.html
This buffer sucks, it doesnt rotate but vibrates and makes a circle motion that isnt complete if that makes sense but I dont recomend this buffer, total garbage. I finished up the area with this buffer and gave up just cause this buffer half assed the job as my bones in my wrist felt like they were clashing together.
I'm sure if you get a quality industrial buffer or even a air powered buffer it would work in a fraction of the time but there a bit too pricey for the job they do imo.