Reddit mentions of Magpul Industries Sling Attachment Fits M-LOK, Black, 1

For 1-1.5k you're better off building it and saving a lot of that.

NOTE: everything under here is my opinion, but I used to build these at a very well known shop and have gather some experience over the years.

Basically Google a simple forged upper and lower receiver. Or go to a local shop they may have lowers so you don't have to go through the ffl crap of mailing it.

Once you have the upper and lower look at the kind of barrel you want. I would suggest personally that you spend most of your money on a barrel and optic. So look into some companies that make a good barrel like white oak and compass lake engineering. The reason not to buy one from a company that makes other stuff is that they get really cheap barrel blanks, then flute it, add a nice finish and a muzzle break and sell it for $300 or a little less. After all that crap you realize they started with a $100 barrel blank and you paid all that extra for nothing. So get a heavy contour 1:8 or 1:7 Criterion chrome lined, or steel if you'd like. This is where your accuracy is and its best not to cheap out here. Especially if you want a DMR style rifle. No less than 18" I would suggest, 20" is also really nice for that extra FPS. Rifle length gas system. And get a low profile gas block with it and have it threaded if you want to put a muzzle break on it.

Muzzle device choice is wide. I like the M4-72 severe duty compensator. I've got one now and it's SICK. That or a J-Comp. I wouldn't entertain any other muzzle devices. I suggest the J-comp because it's cheap and really does work. The M4-72 isn't cheap but is the best one on the market hands down.

After the barrel look at a nice optic, a good budget one is vortex strike eagle 1-6x or an SWFA 1-4x. Both $400 or less. I like the SWFA personally because it uses mil dot reticle and turrets. If you can find a mil dot and turret from vortex then that's even better, their warranty from what I hear is amazeballz.

Next you should look at furniture, this is purely subjective to your whims. But note if you get a collapsible stock you need a carbine buffer tube and carbine buffer spring and make sure it says mil-spec for the buffer tube. I like DD stock and pistol grip, it feels quite nice, but there's a million options and they all fit. Magpul makes nice stuff and some of it is reasonably priced as well.

Next you'll need a handguard. This you don't need to spend a ton of money on, just one that looks nice. Geissele makes a nice hand-guard they are light and strong but it's on the slightly higher price end. They all work, and they all function just fine so get what you think you'll like. Don't go crazy with the quad rails (they look cool but) because they're rough on hands, heavy as hell, and expensive if you want to fill all the unused space with the grips that smooth it out you'll get sick of it quick. M-lok and keymod are the two big attachment systems. I like mlok as it seems to have more variety in parts and is smoother. Key mod works just fine as well.
They all have barrel nuts that come with them usually. Don't get the cheapest handguard because you might get a cheap barrel nut. Most you will find are free floating so you don't have to worry about that.

The last two pieces are parts kits. I just get the regular phosphate "parkerizer" coating bolt carriers and what not. You don't have to spend tons of fancy bolt carriers and shit.

Part of the lower Parts kit is the trigger, you have a big budget so you can definitely buy a nice trigger, but honestly you don't have to. I've been shooting a long time and I've never felt I missed a shot because of my trigger. The mil-spec trigger works great and if you ever did need to use it for self defense you won't be wishing you had a fancy trigger, you'll just be glad you had a trigger that works. You don't notice triggers when you're getting shot at, you can barely move your fingers well enough to reload so it's really not that important a lot of vets might tell you about how they've thrown a magazine into their friends face cuz it flew out of their hands. That being said if you want a nice trigger I like the Milazzo-Krieger MK-II trigger. It's about $225 but it's really nice. Lots of ppl will suggest the geissele SSAE or whatever it's called. They're about the same price but the milazzo-Krieger is much nicer. I've used it a lot but I can't force myself to pay that much for a trigger. But if I ever do that'd be the one I get.

Last lower parts kit piece you'll want is an extended charging handle. The reason you want an extended charging handle is because when you have an optic on your rifle, it can be hard to grab. Strike industries has a cool looking one that's double sided for $35ish. Quite nice and I'm thinking of picking one up after using my friends. Or get a regular mil spec charging handle with an extended latch for much cheaper.

That's about all for the rifle itself.

Magazines are an easy choice, PMAG. Or surplus STANAG or "g.i. Mags" they're the basic aluminum magazine I've got like 15 of them over the years by tactically acquiring them from the army.

BUIS or Back-Up Iron Sights aren't really necessary. But many recommend the MAGPUL MBUS Pros. They are metal and can definitely take some abuse. I doubt you're going to war so it's basically wasted money.

Yo may also need sling mount attachments to go on your handguard. Most buttstocks come with a swivel push button mount already. Magpul Industries Sling Attachment Fits M-LOK https://www.amazon.com/dp/B00ORY7TO0/ref=cm_sw_r_cp_api_R9lZxbP1NC3E8
Something like that would work for an M-Lok.

https://www.amazon.com/gp/aw/d/B00ORY7TO0/ref=mp_s_a_1_1?ie=UTF8&qid=1485311192&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=mlok+qd+sling+mount&dpPl=1&dpID=51XxEGUU5FL&ref=plSrch
It's the only one on Amazon so sure it's what you were looking at, I don't know how the utg one is but the Magpul doesn't stick out far at all and is rck solid... I also trust Magpul a whole lot more than utg.

Fix Janky Sling connection if ya want that is