The Glock 19, Sig 226 and Beretta 92 are all well-designed guns. But it's true, if it doesn't fit with the concealment you have in mind, then odds are you won't take it with you.
I'm guessing that size was the determining factor with all three guns above? So the Glock 19 being the smallest, let's start with that as a benchmark.
The G30 is about the same size as the 19...a bit thicker....so scratch that.
Glock's 26 (9mm), 27 (.40), and 33 (.357 Sig) are all about a half inch shorter in the barrel and stock.
Sig's subcompacts are the P239 series in 9mm, .40 S&W and .357 Sig. The Sig P245 mentioned above is a smaller version of the P220. I've haven't tried the P245, but the P220 is one sweet shooting pistol! I even carried a P220 for a little bit. It's longer than the Glock 19, but not quite as thick. It's one I had to "dress around."
Taurus just came out with their PT-145 in .45. A friend just picked one up...quite small, that's for sure! Especially for a 10+1 capacity.
Para-Ordinance makes about the smallest of the 1911-style pistols. They make them with double-stack mags or single-stack mags..single or double action...
www.paraord.com/pages/single/645L.htmlwww.paraord.com/pages/pseries/p1045.html