...like a smaller Glock or 1911. Which caliber is recommended, something comparable to my 357 mag ?
Check out the Glock 27, it might be what your looking for.
While it lacks the ballistics of the 357mag, it comes standard with 9+1 of 40s&w.. potent in its own right, plus you can swap the barrels in the G27 for 357sig if you want, and 9mm for plinking.
The 27 is a bunch smaller than the Glock 29 10mm, which is as close to 357mag performance as Glock gets.
While many carry a 1911 in some for or other, I find them heavy for their capacity.