I have a PF 9 Kel Tec that can be carried in cargo pockets without printing at all or jeans with some printing. I have two holsters for pocket carry, one an Uncle Mikes for jeans (only the grip prints slightly) and a "Pocket Holster convertible" which shields the outline with thick leather, like a wallet.
No 9mm or higher I know of is as concealable as guns like the 380 Kel tec or some other mini guns.
Be aware, a really small 9MM is a defensive weapon ONLY. Effective with some practice but NOT fun to shoot like larger guns can be. Very small, light pistols with relatively high power for their size pack a pretty significant "kick" all the macho stuff aside. Still, I am comfortable with mine for hot summer carry and even when a larger gun would be concelable but not as comfortable.
A glock 26 is also an option but thicker and more like a revolver in width.
Oh, the kel tec relies on a trigger block against shock and a relatively long trigger pull as a safety but NO manual safety. The Glock you would be familiar with. Kahr makes a nice one too. The Kel Tec has a seven round mag and one in the chamber for eight total, ready to go.