Go with the Overseer's, it uses .45 (unless you mod it to .308) which is VERY common in this game. I'm playing on Survival and it drops most enemies with 2-4 shots.
If you want a strong build for higher difficulties I'd suggest you stick with ADS. That way you can dump PER to minimum requirement for perks and ignore Luck completely. I've played a crit luck build with pistols for about 50h and it was fun, but it also gets old fast. Not to mention that you'd be hamstrung by higher AP cost of weapons with rifle stocks and scopes (if you choose to use them).
You could go for something like this -
http://www.nukahub.com/tools/special?build=37!!934!15453!f3752133!fd7343244!b17323
Bear in mind that you find a SPECIAL book soon after the start, followed by a Perception bobblehead soon after. That brings your total SPECIAL to 30. As for the perks, I included chemist and chem resistant because drugs are fun but you can safely skip these two perks. Endurance perks help a lot with survival, unless you like getting your legs blown off by grenades all the time I suggest you grab them sooner or later. Armorer is nice to have late in the game, Gun Nut is mandatory for ballistic weapons, Science for energy weapons.
If you want to do settlement stuff seriously then you will need to get Charisma to 6 somehow to get the Local Leader perk. I suggest you either sacrifice some END points and perks or completely dump AGI. I've only included AGI in the template because stealth hit multipliers stack up for some nice opening damage on harder targets.
Couple perk traps to avoid (from my experience up to level 60):
- Awareness
- Locksmith 4/4, you only need 3
- Sniper
- Concentrated fire (too high on the tree if you're going for a Luck VATS build)
- Lead Belly - the game literally tries to drown you in stimpaks. I have roughly 450 after ~50h of gameplay.
- Aquaboy 2/2. Only first rank needed
- Cannibal - see the stimpak argument
- Ghoulish, Solar Powered, Life Giver - passive healing is slow, stat gains from Solar Powered amount to very little
- VANS - you got compass for a reason
- Hacker 4/4 - only 3 ranks needed
- Gun Fu - surprisingly enough there aren't that many opportunities in the game where you have an open line of sight to 3+ targets at the same time. Very situational and too high up the tree to be really worth it
- Mysterious Stranger - hardly ever procs
edit: I would also AVOID Idiot Savant. It's really good in the beginning when progression is slow but eventually you'll overlevel the content and the game will become too easy. To avoid this I'd advise you to try and alternate between defensive (or utility) and offensive perks every level, otherwise you will become too strong too soon.