Hi this is my very first post and I am impressed. I went to a gun show today and briefly handled an M&P for the first time. Nice. But to wean me away from my Glocks and XDs, I am going to insist on an M&P Compact in .357 Sig (next to the .45 ACP my favorite handgun caliber). Are these available? If not, why not and when?! Thanks guys.