I've fit literally 100's of WC spindles and the noise from the spindle is very low and just about all the main noise comes from the cutter/material.

I know what you mean about the tool holders, it's like cameras.? you get tied to a specific brand because of the investment in lenses which is where the money goes but sooner or later you have to bite the bullet and invest in better gear and to me, if your replacing the spindle there is no better time.?
Thanks Dean, would you happen to have any links to the kind of thing I should be looking for ? I'm clueless about all this stuff !
If I could only get a new original spindle I may get another 10 years out of it, by which time I think I will have had enough anyway.