To the best of my knowledge the Single Ten is not available in Canada yet, but I could be wrong.
They are pictured and advertised with FO sights, and there seems to only be one model right now. The FO sights can be installed on any Single Six, FYI.
They are .22 only, no .22 WMR.
Seems to be only one barrel length, the popular 5 1/2".
As for which one is right for you, you'll have to decide what's important. Do you want to shoot .22 WMR? Do you desire a different barrel length? Prefer blued?
Personally, I have no desire for a 10 shot-6 shooter. (Did that make sense? Okay, didn't think so!)
EDIT:
Browsing Rugers website, I stumbled upon a Lipey's distributor exclusive model Single Ten, 4.63" barrel, available in stainless or blued. Kind of a handsome piece, but still that awkward 10 shooter thing.