I have been trying out many conceal carry rigs.
My Glock 21 is thick as a brick. My favorite round is still the .45ACP.
I have an RIA 1911 compact frame. It has a single stack .45 in a 6 +1 setup. I had the hammer trimmed to smooth it and reduce the "Hammer Bites" on the meat of my hand.
Another great addition is the "slim grips". This image shows how much thinner the grip can be. They are avail from many makers and even support ambi-safeties.
--Now I just need to find the right holster!