Nice Inuyasha cels can be found pretty much 
anywhere.  He's a relatively easy character to 
find.  Try checking some of the major cel 
dealers like Anime Asylum or Anime 
Museum out.

Kouga's a different story.  Might wanna keep an 
eye on ebay and yahoo japan for him.  I hardly 
ever see him in dealers.

Finally, for Kanna...I've never seen a full body 
shot of her, but I know Anime Museum has a