buffout,jet,cigs,nuka can all be used in the builds.
Then what problems do you have?
3 9 4 1 4 10 10
Traits: small frame. You can also take chem reliant, as, when you're active (not offline), you're going to be on drugs anyway, so perma addictions aren't problem, and drugs will last 1 hour instead of 30 minutes, making gameplay easier.
Drugs: Of course buffout, Jet, cigs and nuka. If you'll be bothered with this drug cocktail, but it's your choice: be PvP ape or get fun from game, you can't get 2 of that at the same time.
Skills: SG, Doc. It's enough, you can tag FA as 3rd skill if you want, or any other skill, it doesn't matter much. As after implemention key binding on stims/SS you don't need FA anymore, except for Hinkley.
For 95% in the eyes to 0 AC person on 50 hexes with 10 PE and Sharpshooter with sniper rifle with enough ST you need:
Penalty: 95+60+50*4=355.
Bonus: (10-2)*16+8=136.
Skill must be: 355-136=219%.
Lv2-3: 109% SG and weapon handling.
Lv4-5-6: 141% SG and even more critical.
Lv7-8-9: 163% SG and sharpshooter.
Lv10-11-12: 181% SG and better criticals.
Lv13-14-15: 197% SG and action boy.
Lv16-17-18: 209% SG and bonus rate of fire.
Lv19-20-21: 219% SG and 66% Doc and right between the eyes (if it ignores helm, if it works like in description, then it's useless and one of the worst perks ever).
Lv22-23-24: 219% SG and 100% Doc and x2 action boy and 22 skill points left, you can get also 90% FA if you tagged it as 3rd skill.
On all drugs 3ST+weapon handling, 6 EN, 10 PE, 10 AG, 14 AP. 56 FoV if it works.
Yes, only 112 HP. You can decrease your IN on 2 and increase you EN on 2 and even take x2 lifegivers instead of 2nd action boy and right between the eyes, but you'll have only like 70-75% to hit in the eyes on 50 hexes with sniper rifle to 0 AC target because of lack of skill. But you'll have bonus of 4+23+20+30=77 HP, total 189 HP.
Personally I was playing pure sniper only before wipe and not much time, those who says "50 hexes shots aren't always" are wrong, as for me 50 hexes shots was in 95% cases, so you better have a lot skill, if your target can see you, you better simply run and hide, if not, shoot, so you don't need much HP. But it depends on your play style. I just kept distance and shot only on max range, making sure that my target won't shoot back because he can't see me, so I was some kind of sneaker without sneak skill. Even my personal opinion is: if you have <10 EN - it's bad, even my sneaker has 10 EN, because I simply can't have less, that's one of reasons why I don't play pure sniper. Another reason is that you need to be not alone, sniper alone can be easily cough, but loner won't do that, as answer on question explains all: why do you need to be pure PvP sniper if you're alone? Trolling them by shooting and running away or what? So scrap 189 HP and make 4 EN 4 IN and remember, if your target sees you - run and cover if possible, shoot only if you have no choice (no walls, corners, almost point blank range, plain desert, etc.)
