Yes the Keller Wynne correctors are useful for any focal ration newtonian between F3.5 and F5.5. I have some info at my site regarding spots and vignetting:
http://www.pbase.com/strongmanmike2002/new_observatory
The corrector is 3" in diameter and about the size one of those older design large Nagler eyepieces. You can see it in the top left of this picture:
http://www.pbase.com/strongmanmike2002/image/72520337
It simply slips into any 3" focuser and your camera connects via an adapter and 6 screws. ASA will construct a camera adapter for your camera/spacer for US$155
http://www.astrosysteme.at/ikreator/...ent_66-en.html
If you wait a couple of months ASA will be releasing a 4" diameter corrector for a 60mm corrected image circle!
Collimation is a little fiddly compared to a SCT but not that bad. I have the CATSEYE collimation set and this is very sensitive for high precision collimation if one deires.
http://www.catseyecollimation.com/
Mike