Just buy a P220 Carry already ... it's an excellent pistol ... I know since I have one. If you don't mind the extra weight, consider an all stainless model. If you'd like a little less weight, buy the standard version. There are numerous Carry models to choose from.
http://www.sigsauer.com/Products/ShowCatalogProduct.aspx?categoryid=37
http://www.sigsauer.com/Products/ShowCatalogProduct.aspx?categoryid=37