IMO get a dedicated 9MM pistol for your first pistol. A 9MM will have less recoil and be FAR less expensvie to shoot and practice with and there are a LOT more great pistols available in 9MM than in .357 SIG to choose from. Also high quality 9MM SD ammo is very effective such as Speer Gold Dot +P 124 gr and others such as Federal HST. The .357 SIG round excels in penetration such as windshields which is why some agencies use them but you don't want or need that in the home.
As for selecting a pistol you really want to go out and handle as many as you can and then from the ones you like try to rent them and try them out. Shot placement will be the most important aspect of defending ones self and not missing the target that could lead to collateral damage. That is why practice practice practice is important.
My choice for .357 SIG is the SIG P229 but again I strongly suggest you consider a 9MM - especially for a first pistol purchase. If you insist on .357 SIG the P229 can be converted to .40 by simply buying the SIG factory .40 barrel. For 9MM you would need something like the Barsto 9MM Conversion barrel. There is even a .22 LR conversion kit for the P229.
Last edited by sigarms228; November 4, 2012 at 11:45 AM.