I have gone through this process over and over....
I'm 5' 9", 170#. I live in AZ where it's shorts and light shirts almost all year long. Shorts with no belt are sensitive to a gun's weight and bulk. I personally don't like my pants listing to starboard due to pistol weight and wearing a belt with shorts is just uncomfortable to me, plus many shorts have loops that are too small to fit my carry-belt. Polo style shirts, and T's are sensitive to bulk (printing).
I've spent money on three different ccw guns before finally deciding the J frame is best for me.
1st try: Ruger SP101 3" 357mag. Loved it, but: heavy trigger, heavy in general, didn't like practicing with 357's so I practiced with 38's and carried 357. Ultimately it was too heavy and bulky for me to carry every day.
2nd try: Kahr PM40. Super small, lots of blast and muzzle flip, fit in my pocket really well, but gave me blisters every time I shot it, so I never shot it (bad).
3rd try: Star PM 9mm. My dad's gun. It's a single stack 9mm smaller copy of Browning's Hi-Power/1911. Great fit, shoots fantastic. I decided I didn't like to carry this in Condition 3 because it has no grip safety, and I was unsure of this gun's firing system. Condition 2 is no good, that leaves Condition 1 which is close to pointless.
For now I'm using my dad's stainless Model 36 he bought in the seventies. I love it!! It shoots well, fits in my pocket with or without a holster, and I can handle it well enough to actually shoot it. I shoot in on a bi-weekly basis and my confidence is high. I keep a speedloader in my off side pocket.
When the funds free up I'm getting a hammerless J frame. All modern J frames are +P rated btw
There is a lot of trash talk on this 'inner-net about how anything under a .40 will not be useful. BUNK! 9mm and 38's have stopped a lot of bad guys.
The other pistol I considered for ccw is HK's USP compact in 9mm with the LEM trigger. I love the LEM trigger, and I am a big fan of HK's mag release lever (not button, lever), love it. It's hammer fired with no safeties, no buttons, just pull it and stroke the trigger. Great gun, being a double-stack, it's just too big for me to ccw with. If I lived where I could wear a little heavier clothing, this would be my choice. Today it hit 112F, so I'm not wearing jeans or a sport coat any time soon!!
This question is highly personal

You need to find what fits you, fits your clothes, fits your lifestyle, and fits your combat accuracy with recoil control and Practice Practice Practice.
The bottom line is: You can't stop what you can't hit, and you can't shoot if you don't carry.
I had a great time reading through the thread. Lots of great advise!
Have fun