Been carrying a G27 for 6 years now, and have no complaints. It is way more accurate than it should be and conceals fairly well. I give it top praise, and that's saying a lot from a guy who hated the looks and feel of a Glock. I never met a Glock of any shape that either fit my hand or impressed me with accuracy (and I tried).... until the G27...it just works for me. I can't see me ever buying another Glock, but I like this one.
I ended up with the 27 by default because that's all they had in stock and I needed a smaller gun than a 1911 at the time (for deeper concealment), so I went with it. I would have liked the .45 acp model but they were on back-order. With 10 rounds of Cor-Bon 165gr JHP +P's in the gun and a spare mag, I do not feel lacking in firepower.
All that said, you would be served well by either the 26 or 27. I've never been a fan of 9mm in any shape or form, but there are plenty of top ammo brands that will get the job done in that caliber these days.
I prefer my 1911 Commander, but the extra weight makes a difference sometimes.....and with my bad hips and knees, the lighter G27 is appreciated.