Just did my lenses, here's my 2 cts....
I first bought the Wolfgang Lens Repair Kit ( http://www.autogeek.net/lenshowto.html
) , as it got very good reviews, it came with a sealant (important), two polishing compounds & a nice 'drill/polisher' pad system.
It worked pretty well, but during the first/'coarse' polish, there were several yellow patches that just wouldn't come out, no matter how long I went at 'em.
I remembered during my 'what's the best lens repair system?' research that 3M's kit used different grits of sandpaper. It was only $23, so I went out & got it & then started over. As I guessed, the sandpaper cut thru EVERYTHING, and after 3 rounds of descending-strength grits, I then switched back to the Wolfgang stuff for final polishing & sealing.
WOW...they look GREAT. In hindsight, I'm still not sure if there's one single approach that would be as well as that combo, but that's an awful lotta $$ for lens repair. The 3M kit can cut thru the bad stuff, but it seemed kinda weak when you get to the final/fine polishing; it only has one polishing compound (and only a TINY amount of it), and no sealant.
I'd say get the 3M kit & then look for some small bottles of fine compound(s) and a SEALANT, which is crucial for helping your hard work last for as long as possible.