Re: help with first conceal carry pistol
Since there have already been several suggestions, I'll give an opinion on your next set of questions.
Night sights - I have them on my Glock 17 and they're really great for shooting in low light. If you're actually shooting in the dark, you'll (hopefully) be using a light somehow and I haven't found that they're necessary for night shooting. However, the Trijicons that are on my Glock are really nice in the day or night, so I would recommend a good set of Novak-style night sights on a carry gun.
CT/laser grips - no. Practice sight alignment, point shooting, and basic defense shooting. You don't need a little red dot you've come to rely on to get blocked by your hand in an awkward grip in a bad situation. It could cause enough of a hesitation to be the difference between you coming home or not. For a truck gun like a Taurus Judge or something - sure, stick 'em on there. But something you're carrying every day that you need as simple as you can get, you don't need 'em. Also, the bulge in the grip <span style="font-style: italic">could</span> potentially cause a fabric snag. I know, not like anything else on a gun can't; but you don't want to have that extra chance of catching it wrong on a shirt or hem.
Ambi controls/thumb safeties - do you like them? Are you used to them now? I carry a Smith and Wesson M&P 40 compact, no thumb safety, stock pistol. Ambi controls can be handy if you lose dexterity in your strong hand, but I would say practice shooting weak handed extensively. Practice until it's boring because you're consistently making good shots. Practice drawing and aiming with your weak hand. Figure out how the mechanics work beforehand so you don't struggle when split seconds may count.
Finally, in response to your original question - are you likely to be in a situation that requires you to use deadly force? Do you spend a lot of time in parts of your area that have violent crimes? If you don't, ease of carrying and small size are going to be your best friends. If you're routinely in a "shady" area, capacity and access are your standbys.
I'm comfortable carrying my M&P compact. It's probably too much for my area, but it's comfortable and comforting to me. I have 11 shots ready, and if I'm out in an unfamiliar situation or very public place (like a downtown event), I have another 10 with me. That should be more than enough to handle any threat I could encounter. If not, a)I really f*cked up; and b)my wife also has 21 shots
I'd recommend either an M&P Compact in 9mm or a Springfield XD Sub-Compact in 9mm, if it's just an everyday "don't expect to use it" carry. Otherwise, you may want to look into a Glock 19 or a duty-size XD 9mm.