galco king tuk will serve you well.
The 23 is just about a perfect weapon. I carry one every day. In summer I can pocket carry it (in a holster, shorts and untucked shirt is great), and all other times I carry either IWB or OWB. A good belt and holster combo is the most important part of the Carry Package. Do your :homework and you'll find what works for you.
I can carry my my G23 in a Owb easy in the cool weather when I have a flannel or jacket. My G27 use to be my hot weather gun but I find that large when Its 80+. I will use my XDS for those 2 months. JME
If you like the .40 then I am sure a 27 would be easier to conceal but I also understand it is fun, but expensive buying more guns. Personally I find concealing the G30 a bit of a pain at times but by all means it is manageable. I would suggest going to somewhere that has several holsters you can try out while wearing your every day clothes and you make the call.
I use an Alabama Holster "Offside" most often, but I do have an AHCo. pocket holster made for it. It's just that my G23 usually rides in the Offside anyway, and it fits in the pocket and breaks up the outline just about as well as the dedicated pocket holster.
The trick is to wear a good belt so it doesn't pull your pants low on one side. it just has to look like a wallet or phone or keys or any of the other pocket junk people carry. And it does, I promise.