I'm in the market for a SP2022, and I am pondering on what caliber to get. If I go with the 9mm, can I later get a conversion barrel for the .357SIG and or .40sw? Or does the .357SIG conversion barrel only work in the .40sw version? I might have to buy both! Also, I really want the German made version as oppose to the one manufactured in the US. Any tips on where I can purchase one new? Thanks!