OK, so I'll try to get both sets of questions into this answer. I upgraded from DVD, I think it was 10.6.3. Then I did several checks of Software Update. That's what got me to 10.6.8. I see that you mentioned the combo installer. Will I be able to find that on the Apple website, or is it somewhere else?
Now, with the printer prefs. I do have an HP 5780, which showed up in the initial printer list. When I did the reset, even that one disappeared. However, I just happened to have it connected via USB (didn't know it was even connected since I never use it for printing). Anyway, I turned it on and was able to add it to the list, and print a page. (WooHoo, at least it's one success). However, my main printers are Xante Accel-A-Writer 8300 and Xante CL30. Both are connected via ethernet, and neither are showing up to add to the printer list. I've downloaded new drivers, but no success. I saw some little hint, and now forget where, that makes me think I can now only connect printers via USB. If that is true, the 8300 is utterly useless now. The CL30, I think, has a USB option, but I have to investigate further. These are expensive, huge production machines and I have to find a way to make them useable.