I've not use the Sig you mentioned, so I can't say anything good or bad. I have read that the other Sig .22 called the Mosquito has not found a large following because of numerous problems. Nonetheless, I hope to add one to our collection at some point and see if the many complaints I've read have merit.
Another .22 semi that emulates a full-size handgun is the CZ Kadet. One could also get a Glock and a .22 conversion kit.
You should at least look into the better .22lr semi's as well. The Ruger MKIII and Browning Buckmark have been around a long time, and provide a great amount of performance for the dollar. A nice BM can be found new in our parts for about $279, and it is ten times the pistol that the P22 is, for about forty or fifty dollars less.