Knives in Chinatown
The Chinese are not knife obsessed like the Japanese are (I said the same thing in respond to another thread in the Asian board). So no you won't find great knives in Chinatown. Check out Bob Lauriston's suggestions. I also wonder about you wearing out your Shun Classic. That must be a lot of knife use to wear it out.
The best knife shop near SF Chinatown is Columbus Cutlery. In Chinatown, the Wok Shop has a great selection of kitchen tools at great prices. You might also check out Kamei and Forest Restaurant Supply, which has crazy low prices thanks I think to direct imports from China. http://www.forestrestaurantsupply.com
For Japanese knives you might want to visit Hida Tool in Berkeley or The Japan Woodworker in Alameda. Soko Hardware in SF also has some.
358 Columbus Ave, San Francisco, CA 94133
Kamei Restaurant Supply
547 Clement St, San Francisco, CA
718 Grant Ave, San Francisco, CA
1698 Post St, San Francisco, CA
Woodline Japan Woodworker
1731 Clement Ave, Alameda, CA
Hida Tool & Hardware
1333 San Pablo Ave, Berkeley, CA