No manufacturer is making new pistols chambered for the .22 short, and ammo manufactuers are also rapidly dropping that caliber (if they haven't already done so). This comes as a result from the ISSF's rule changes to the rapid fire pistol discipline in 2004, only allowing the use of .22LR pistols very similar to those used in the standard pistol event. Hence there is not much of a market for the .22 short, as it didn't have much else of a use.
For second hand pistols, look for the Walther OSP, or similar.