Easy work. Ten minutes.
Threaded with standard profile is hard to come by. For highly accurate stock barrels I would go with shilen or lilja. For close to stock profile and threaded I would take a look at zimmerman arms barrels. Or you could PM Texmex about this project, I have heard that he's put together some nice 10-22s!
Guy named Que on rimfirecentral.com will thread the stock barrel, chamber it re-install the sight for $60 or so.
I don't want to deal with a gunsmith.