I am assuming that your .357 is a magnum not a sig or any other variant. A .357 mag will stop a BG (or more) very quickly, even with relatively poor shot placement. But you better not miss cause sheetrock don't stop 'em all that well. Inside a house (or were collateral damage needs to be kept at a minimum) go with Speer Gold dot hollow point .38 special +P's or Magsafe ammo (though i have never used Magsafe myself). If you really want knock down power and range load up with the magnums! I only shoot the .357 mag's myself, but i don't use my GP100 w/ 6" barrel for bedside protection. Its for coyote's at 100 yards.
As far as were to buy them on the west side, I can't be of much help as i am new to the area myself. hopefully someone else might enlighten you on that. Can you make it the the east side? or just downtown?