I use the Canon N656U slimline scanner to scan 
some of my cels, it works really well. The bed is big 
enough to get your cels up to the registration holes. 

The bad thing is that it's slooooooow and that the 
image sensor only does a good job when stuff is 
right on the glass. If you try and scan non-flat things 
in it, then the scans will come out fuzzy. Chack the 
link above for an example. You can see things fuzz 
out along the edges of the computer where the bevel 
starts. 

Plan on about 40 seconds for a full-bed scan at 
72dpi and much much longer at 300 dpi. Maybe the 
higher up models have faster scan motors, but the 
image sensor technology is the same across the 
slimline scanner lineup, so the depth problems will 
persist. Hope this helps! ^_^

-c