Stainless, without a doubt. The whole tone thing is BS. Both Tom Anderson and John Suhr agree that stainless is the only way to go, and there's no real difference in tone. It's basically all positive without any negatives. The frets feel like playing on glass, and they never get grimy. I've also noticed that my strings actually don't get as dirty with stainless frets, too. Just be sure you get a top notch luthier to install them for you. Nothing worse than having spent big bucks on a shitty fret job. I personally recommend Michael Tuttle @ Best Frets. He's pretty much the #1 guy when it comes to refrets with stainless, and he's pretty well known for balling fret ends ala Ibanez J-Customs. It's expensive, though. Joe Glaser is also a great guy, and he'll PLEK the guitar for you. Tom Anderson also does refrets, and he's a veteran at working with stainless. He actually has a guy named Bruce that does it.