@coyote: I purposely refrained from commenting on accuracy because I haven't shot my T-bolt enough to know. From what I've seen or heard, the T-bolt accuracy ranges from very good to...well, good enough for hunting but you won't win any matches. Accuracy can vary from rifle to rifle within brands, but still, I think your best odds for getting a tack driver out of the box (if that's what you want), would be either a CZ or savage, with me leaning toward the CZ.
You're a more experienced squirrel hunter than I am, but for me, the lowly .22 LR worked fine for shooting a squirrel out of a tree. I would have to wonder if a .17 HMR might be too destructive. With a .22 WMR for squirrel, I would lean toward a solid point, rather than a hollow point or a plastic tip expanding bullet.