I've no idea about collimation, but I'm impressed by what you're doing with that small sensor! Good stuff, Ian
I know it's the wrong thread, but I noticed you asked about the 183mc in another thread. I thought that maybe something with bigger pixels like the 533 might be good so that you have a better chance of imaging at native focal length as well as with a reducer on your scope? At (what I guess is) 2000mm focal length, the small pixels in the 183 will be a handful.