I'd say any of the "squirt gun" style classic .22s will work just fine. Look at the Ruger MkIII and 22/45, Browning Buck Mark, S&W 22A, Beretta Neos, and maybe an old Colt Woodsman if you can find one. The SIG-Hammerli Trailsides are also excellent pistols, as already mentioned, they're just a...