My first choice would be a TX200 in .177. Accurate, hard hitting, and oh that trigger(adjustable). Mine is set at 2lbs.
Crosman Premier 7.9gr CPL`s in the cardboard box or JSB 8.4gr pellets for out to :D if you practice, and Beeman/H&N Crow Magnums for under 25 yards on small pests.
Good mount...