Fuji HRT810 is a perfect fit in 8x10 film holders. I can't vouch for other films. Shoot at ASA 200 and develop in HC-110 and Rodinal. Print dev is too contrasty. You get a beautiful long tonal scale. Just be careful, the emulsion is softish, and there's twice as much of it. It contact prints and scans fine, even with the double sided emulsion. I clip a corner so I know which side is the "original" so I can print the right way if desired. it's mostly a force of habit though.

oh, and you can cut it to whatever size and load it with a red safelight.

Here's a link to some stuff I've shot on X-ray film. You can pull the developing details off the description in the images.

http://www.flickr.com/search/?w=30767964@N02&q=x-ray