I am sure Andy at Kudos had 60mm spacers, but that was only as he had the wide arch kit. They are just for show really, some say they ruin the handling, but I had 25/30 on my Zed and did not really notice a difference.
My only rule when it comes to spacers would be to buy the best quality ones I would not go over 30mm and given the choice of spacers or new rims with the correct offset's . . . rims win hands down