Before you go too nuts - Tisas apparently plays fast and loose with JMB's numbers - I posted it in another thread as well. Not a big deal if you're never going to start changing things on the gun...but if you decide to rebarrel it, or make some other changes, you might need to do a lot of measuring first.
I just got a notification earlier in the week that Buds and GrabAGun both have a bunch of Colt Combat Commanders in 9mm in stock (steel frame though, so probably not what you're looking for)...