Bought my first MOS model, a 34. I plan to install a RMR on a FC OPF-G. Most of the pics I see of RMR outfitted Glocks have taller sights, I assume for a co-witness. As I said this is my first MOS model so I am looking for both an education and recommendation on what sort of sights I should also be looking to upgrade to. Thanks.

I'd suggest unless you plan to carry this, you just pull the sights.   With an RMR I've found I never use them after a "break in" period learning how to pick up the dot.

Dawson Precision offers a couple of different height sights to co-witness...plain black around $65/pair... I just ordered a .385/.395 pair for a separate project with raising the sights on a Recover Tactical brace...

the height added by your adapter plate needs to be taken into consideration, make sure you look for /ask guidance for an MOS installation...the guys at Dawson are very helpful.... my RMR is milled into a shorter sight radius G17 without a plate by (BattleWerx)... the sight is the fixed Heinie Slant Pro (.225/.245) originally on the pistol,  and I am able to see a sight picture through the very bottom part of the lens of the RMR... I do not want any more of the sight obscuring the sight window than it currently does... regards Les

I have the same gun, same setup and I have Ameriglo GL-429 sights on mine.  They are a great option if you want black front and back.  Cost is around $40.

Is lower 1/3 an option? The absolute cowitness sites look like they are a mile tall. ridiculously tall.

Yes, the Ameriglo sights I mentioned are roughly lower 1/3 with the setup you are getting. Might even be a little lower.

Ameriglo 429.  

Gonna have to trust us on this one

Here is how the 429s co-witness with the exact setup you are getting.

That's money! Thanks

ETA: Ordered

10-8 sights and be done with it.

Ameriglo GL-429 

Yup, I ordered them. How difficult are they to install? I have never installed aftermarket sights on handgun that wasnt a simple machine screw bolt on. I cant help but look at this dovetail thing and wonder how badly i would mar up the slide trying to drive it on. Suggestions please.

First 2 sets of sights I ever installed where on a glock 34 and 17. I used a vise, a hammer and nylon tipped punch, Loctite 262, and a front sight tool from amazon.
I watched a few videos on YouTube, these 2 videos I found the most helpful.
Video 1
Video 2


It wasn't that bad with the hammer and punch, but I did end up buying a sight pusher and find it way faster and easier. I have installed a few sets of sights with the pusher, and am really happy with it.
https://sightpusher.com