Re: Which 10/22 tactical stock and where to buy it?
Look at the Bell & Carlson Tactical/Varmint stock. They have a cutout for rear bag, front sling stud/bipod mount, and a comfortable grip contour (for me anyways).
It's a great stock for a bench gun, as it's kind of heavy relative to the oem stock. It really comes down to what you're using it for though.
I've also used the Hogue stock. Granted it's not as firm as the B&C and makes barrel contact with a bipod, it's a great solution for a lightweight stock option if you're not shooting prone or from a bench.
Stockystocks, midway, brownells, etc... most sites will have these available last I looked.