Boothe Design has some spacers and a lot of other stuff. Reputed to be very high quality. Someone posted that he has more available (like 100mm spacers) than show on the website.
I'm happy with my OEM 5mm spacers and worry about wear on the bearings with too much spacing.
Please, I know plenty of folks have done it and I've only heard of one bearings problem. And we all know bearings can wear out anyway.
