If there is any gun in the world that there are more parts for then the 10/22 I would be supprised.
Get a 10-22. If you want a 22 that looks like an AR get the S&W
As far as cost goes, forget a 10/22 and a .22 AR, get a Marlin Model 60.
Get your 10/22 and install aperature sights (like Tech-Sights sells).