Glock 19 milled for an RMR (ateiguns.com, pro cut), couple preban 19 mags for carry, 17 mags for range/home. Five cases of ammo, one of which is HST (first thursday of every month is 50% off HST at targetsportsusa.com). Coursework from a reputable trainer (as an example Sig Academy HG 102, 103, 104, Low Light, CCW, CQ pistol, pick up in the progression wherever you think you are...skip 101 if you have touched a gun before). Dry fire a ton (manipulation, malfunction clearances, draw, transitions, reloads...almost everything you need to be safe, efficient with your new choice, and competent). Right around when you're buying a second 19 with RMR and running low on ammo you're putting your third RSA in your now-range gun (the spring counts dryfires as well as live fires), and you're getting super comfy with the platform. Feed the second one 300 rounds of the HST and now that's your carry gun. If it won't feed 147 HST step it down to 124 or 124+P (the 147 OAL is slightly longer). Get force on force training. Get medical training. Try out USPSA or IDPA, stow your ego because you are going to suck at first, but the communities are great and participation will lightspeed fast-track your mechanical skill, efficiency, and gun handling.
You're going to have to experiment with what fits you and your body/carry location, but the 19 is pretty universal for a good balance of being concealable and still having someplace to grab the damn thing. Little guns like the 43 or 365 are fine but they suck to shoot, relatively speaking, in my experience. They have their place but based on your post you aren't looking for one. If you can pull off a 17 or 34, go for it. In fact, a 19 in a 17 or 34 AIWB or IWB holster (counterintuitively) does real well, the longer holster provides good stability. If you can take the extra length on the back of the grip of a 17 or 34, go for one of those I guess. Some people can make those work but in my uninformed opinion the juice isn't worth the squeeze there. 48/43X an option as well but the dot market/WML performance isn't there yet and for me dot is life, WML is a must.
Any other reputable manufacturer's striker pistol is going to be suitable provided you test YOUR particular serial number with YOUR carry ammo, don't read reliability reports on the internet. VP9 (I own one, love it), PPQ, M&P 2.0, P320 are all reasonable options. Shot them all, they are all fine. Depending on how goofy you want to get with aftermarket, the availability of preban magazines, holster selection, simplicity of action all sort of favor the Glock and are why I chose what I chose.
I shoot 8" steel at 100y with the 19 with a dot, generally don't go 10/10 but from the size of benched groups at 25y I wouldn't expect to. That, to me, says this thing is as accurate as I need it to be.