I would pretty strongly encourage you to save up and go with the 617. Great revolver.
I sold my Single-Six shortly after acquiring a 617. I found the Single-Six to be a limiting gun, with so-so accuracy. My groups picked right up once I started using the S&W, even though it has a 2.5" shorter barrel than the Ruger! I think the S&W's shorter "lock time" (i.e., hammer drop) plays a role in its superior accuracy, but Single-Sixes shooting .22 LR are also haunted by the problem of (frequently) oversize bores, which can impede accuracy as well.
Single-Six is fun, nice looking, and reliable, but in my experience, the S&W 617 is simply a more much serious shooting revolver -- which makes it
more fun than the Ruger. Precision is fun.
(Also, you can really burn through some ammo with the easy-to-load, 10-shot Smith DA action. When you include time spent stuffing magazines, the 10-shot 617 is actually quicker to load than a comparable .22 autoloader.)
No experience with the Taurus.