Any advice on optics for an AR 15, 100 to 200 yards would be appreciated.
Any low Profile Variable Optic. Vortex Strike Eagle is a good place to start. 1-6, 1-8, or even another brand 1-4.
And as far as your optic question, I am planning on getting the Primary Arms SLx 1-6x24mm. Take a look and see what you think. I think it will operate well as a close range red dot because of the illuminated reticle and it has magnification for long range as well. Don’t have it yet so I can’t speak from actual hands on experience.
Primary Arms ACSS 2.5x or 2x is really perfect- it allows 0-500 use with good eyes, and with my bad eyes, 0-300 all day.
I have the 1x and the 1-6x24 as well, I love them all - but if I could only have one option,
The 2.5x
My eyesight is the key to this acquisition , I appreciate your input.
Where can I get a scope installed ?
Just do it yourself. All you need is a vertical line on a wall and a level on the rifle.
I use a door or window jamb for my vertical. A plumb Bob on a nail works well also.
ACOG 
Seriously I can’t afford an ACOG, but I’m insanely snobby when it comes to weapon sights. Iraqveteran8888’s review on them is one of my favorite on the ACOG, and he goes over comparisons. Plus after what I’ve seen at the rifle range I’m convinced it’s worth it. Those kids were smacking the paper targets at 500 yards. I might get a vortex to hold me over, but it’s just going to be a bridge until I get an ACOG.
Thank you