You can usually find X cels on Yahoo Japan, 
there's been one of Yuzuriha on there for a long 
time.

I snagged one of Arashi unsheathing her sword 
from her arm, but I'm not keen on parting with it 
[and it hasn't come in yet either].  Just keep 
your eyes open.  There was one cel of the two of 
them on eBay not too long ago that went for cheap 
[~125$]

goodluck