I carried a 642 for several years as my only carry gun, and I still carry it on occasion, so I'd most likely go to that, or join haywood and carry a pair of them, which I've also done (IWB + ankle).
I've also been carrying my 1911 Govt Model around the house, so that could be a viable option. I'd have to get a good IWB holster for it before I'd start wearing it out-and-about. I only have a cheap Uncle Mike's IWB, which is generic enough that the gun rocks back-and-forth inside the holster (with bluing wear to show for it), has pretty much zero retention, and reholstering safely can be tricky.
If I were going to buy something new, I've considered getting another 1911 specifically for carry, maybe a Commander or CCO, or go old school and get a Colt Classic or SA Mil-Spec. A Kahr P9 has been on my short list of 9mms I'd like to get for a while. Of course, the Sig 365 would be a good option; I'd have to see how it fits my hands, though.
I've also considered getting a PX4 in .45ACP since I have the Compact in 9mm and really like it, and I'm familiar with the manual-of-arms. I know Beretta has them in their catalog, but I don't think I've ever seen one for sale.
I could just use lower capacity mags for my 92 and PX4, but I have heard that with some guns the reduced capacity mags don't work as well/aren't as reliable. I would probably get some and test for reliability, and put them into service if they work acceptably.