whoa whoa whoa, didn't read all the posts because I feel you need to read this ASAP!!!
I too have felt out the options for neighborhood varmints, and believe I have found the ideal set up. I've had high velocity, expensive air rifles and was not impressed.
so here ya go- Get a bolt action .22LR, I got a Marlin model 60 used for $60 from my local toy store. then buy a brick of aguila colibris, you will be in business!! The colibris will shoot accurate and are less noisy than an air rifle....but, they are also more powerful i.e. more knockdown!!
I have shown this set up to lots of people and they are blown away at how quiet it is. Let alone you still have the option to shoot hot .22 rounds. It puts squirrels down and my buddies and I have even used them effectively on prairie dogs when we find those colonies right next to a road hehe.