.22cal would be a lot more appropriate for coons, and even those can be a little light. I like my to set my PCP rifle for 750fps with 21g beeman kodiaks for raccoon, with that I would only take head shots, my experience. On squirrel the same pellet @600fps will go straight through at 40yds.
Gamo's are fine and accurate enough for 50yd shots, but, keeping the scope in place requires a sturdy mount, don't bother with that so called "recoil stop" that come with it. Get a B Square and crank it down.
RWS's are excellent. The 350m in 22cal. will drop a coon if you can do head shots in the dark.
I would definatley go with the .22 for what your after, and even then I would find some 18-22g pellets that are accurate. If you've never seen one you will be surprised at its capabilities.