For the regular 10/22 carbine, I like the looks of the Zephyr sighting system. I don't know if it's good or not, but I like aperture type sights.
As for a scope, I have a Leupold Vari-XII 4-12x40 on my 10/22. Mine's a Volquartsen Custom 10/22 though, and I wouldn't consider putting a scope like that on a plain 10/22. I'd probably go with a Simmons.
I'd definately like to hear opinions about the Zephyr system. I'm planning on buying a plain 10/22 as a beater and I'm going to leave it with open sights.