My understanding is the 'Busa pistons are lighter than the SV pistons, but do not increase the compression ratio. Theoretically, the bike can rev faster; on the street, I doubt you'd see any advantage. Taking apart perfectly good cylinder heads to shave a mm of gasket material also strikes me as a poor idea.
Higher compression comes from machining the heads and using thinner gaskets. You also have to hone the cylinders. It's an expensive and not an easy mod. IMO, it's a mod for people who have done every other mod, and are still not done fiddling.
EDIT: My comments are based on my assumption that you're looking into this as a street mod. If you intend to race in a class that allows this modification, that's a different matter.
