Ok I decided on my plan. I'm gonna convert my Custom II to 460 and buy a 4" Kimber. So you all ready for more questions? 1. Most of the 4" have alloy frames. I am pretty leery of an aluminum frame, should I be? 2. I can't decide between these three. Pro Carry II black steel slide/alloy frame Pro Carry II SS slide/alloy frame Pro Carry HD II all SS They range from $728-$928, but what I can't figure out is why the all stainless HD II is cheaper than Pro Carry II that has an alloy frame?