Floor is rotted out at the rear seat mounts, so I doubt those will help you any. Sorry.
Here are some pics of the engine. Not sure what vaccum canister you are looking for, but please point it out on the pic, and I'll be happy to let you know.
http://www.qtm.net/~persot/Parts/944/engine1.JPG
http://www.qtm.net/~persot/Parts/944/engine2.JPG
I do still have the air box and snorkel, I pulled it off the AFM and it's in the trunk. Tip of snorkel to the AFM mounting, $20 plus shipping.
Complete rear brake assemblies down to the trailing arms as described, $125/pair.
I've got some pics of the car here:
http://www.qtm.net/~persot/Parts/944/944-1.JPG
http://www.qtm.net/~persot/Parts/944/944-2.JPG
Including rims:
http://www.qtm.net/~persot/Parts/944/rim-1.JPG
http://www.qtm.net/~persot/Parts/944/rim-2.JPG
http://www.qtm.net/~persot/Parts/944/rim-3.JPG
http://www.qtm.net/~persot/Parts/944/rim-4.JPG
Thanks,
Grant