I own and carry a lot of stuff in this category. I would ask what it's for, and what else you have.
If it's for carry, are you going to dedicate yourself to the 1911 platform? If so what other 1911 pattern guns do you have?
If it's just for fun steel 9 commanders are baller.
If it's for carry and you have a full size get the CCO pattern with an aluminum frame. Perfect summer t shirt gun.
if it's for carry and it will be your one and only get a 9 lightweight commander and then sell all your other guns and buy a spare. You won't like any other guns after that.