First off nice profile pic!
Now to business. The .17hmr is going to be a little light for coyotes. It will work well for squirrels and rabbits though. The .22WMR will not be a whole lot better for coyotes, but will allow for a touch more margin for error. Both calibers are pretty plentiful, and are accurate at whatever distance you would want to take an animal at humanely. My personal reccomendation is the .22WMR, only because more rifles are chambered in that caliber.
If I were you, I would try to borrow a .17hmr and .22wmr from a buddy, or your LGS, and see what one you like better.