I just recently won a Classic Performer accelerator for the MAcintosh Classic. It is AWESOME. Its what the classic should have been, 16mhz. It is so much better than 8mhz, and it runs a lot more stuff. It is still the same processor, but a 16mhz variety, even though the site says 25mhz.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5111955747&ssPageName=STRK:MEWN:IT