Fanime con is located in Santa Clara California 
(San Jose).  
It begins March 30th and ends April 1st.
For more info:
http://www.fanime.com/

The cel dealers going are:
Anime Link
Asylum Anime
Ed Noonchester
Nichibei

I also heard Usagi's House coming from Japan, but 
they are not on the program, they will be in Anime 
Link's booth.

They all will have lots of cels and usually bring 
stuff that isn't on their websites and stuff.

There is also a cel meeting Friday night where all 
the cel collectors and dealers get together to show 
off their cels and to trade!

It's always a lot of fun and there are lots and 
lots of yummy cels at Fanime.  I would say that 
next to Anime Expo, it is the BEST convention to 
buy cels from!!!