You gotta go with the 1911. Best pistol design ever (IMO). I have a Springer loaded model, and they are great guns. Most intuitive shooting automatic pistol I've ever shot. You already have two polymer pistols. Other than that the only one I can comment on is the XD. Great gun I've had one for 5 years and shot it quit a bit. So reliable it's almost boring. I can't shoot a Sig P220 worth a damn so I haven't bought one.
If it were me, I'd ditch that HK 9mm and get the 1911 and the XD, but that's your business. Good luck on getting a good price, and I doubt you'll be disappointed in any of the reputable .45's you are considering.

