I buy the rolls most of the time and make my own when I want a fine grit for polishing but for general re-sharpening I've had good luck with the Norton 120 grit belts and then hitting them with a 300 grit I made and finally a Lee Valley leather belt.
Absolutely shaving sharp EVERY TIME in just a matter of minutes.
I'm sure with the size of your collection, honing and sharpening probably feels like a full time job. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />