Your cylinder, assuming it is stock, is aluminum with a Nikasil coating (Nikasil is ha hard surface that will not wear, or at least not very much) if you tried to bore it you would be taking the hard coating off and be down to Aluminum, and we know how long a piston would work in that environment. You can have you cylinder re-coated, there are several companies that do it, US chrome, Millenium technologies and many others, for about $250 they will redo your cylinder to like new condition. If there is serious damage they can usually fix them. The other option is to sleeve it with a cast iron sleeve, you could then bore it to oversizes, I wouldn't do that unless you were looking for a big bore, then it might be a possibility. I would caution buying a cylinder off ebay, if you did you would probably have to have it coated as well.