Usagi's just uploaded quite a few Fushigi Yugi 
cels at very reasonable prices. Wait, was it 
Usagi? let me check...yup it is. Here's the URL:

http://www.usagishouse.com/

And Anime Chaos always has a large selection of 
Card Captor cels. Here's the URL:

http://www.animechaos.com/

There are a lot of sites that carry cels from 
both FY and CCS, but those two were the first to 
jump into my head. ^_^ Happy hunting.

MeganD.