Goodness knows this is a beautiful sequence, and 
I don't even know if these people accept offers. 
It looks like most list these as NFS, so good 
luck. I haven't emailed these people personally, 
but am rather tempted to [although I won't].

http://animejewell.rubberslug.com/ has not one, 
but two cels from this sequence. Very good ones, 
I might add. 

http://www.glass-heart.com/ has a perfectly 
centered cel from this sequence.

http://www.asylum-anime.com/ has a few cels of 
Sakura only from this sequence.

http://drakonia.rubberslug.com/ has some 
beautiful cels of Sakura/Li together. 

http://www.o-ka-ne.com/~nessa/CCSwaltz.html -- I 
have no idea who this is but I found it on 
google. It's NFS, of course, but whatever.

Good luck!