I don't coyote hunt, yet. Intend to try some next year after I retire and have more free time.
I do have several AR15s. Barrel lengths from 24" to 10.5". Barrel weights from "skinny/lightweight" to "heavy/bull barrel".
The best groups I've ever fired is out of my 24" bull barrel gun.
But, the 20" HBAR clone and even the 16" lightweight barrel guns are pretty close. My last carbine build (16" lightweight chrome line barrel from RRA) is very accurate. I'll do some hunting with it. I've never loaded anything heavier than 62 grain bullets. Mostly 55 grain bullets. I'll be trying some 45 grain bullets in that 24" gun as my initial test showed it shot its best groups with some almost 30 year old reloads I'd loaded, but not shot in my M700 varmint special back in 1984.
I would definitely have a free float tube on your rifle. I'd have a bipod/bipod mount so I could shoot it with/without the bipod. I found, many years ago, that even though I had a 4X12 scope on my varmint rifle (ground hogs and crows back then) I usually kept the scope on 8X for almost all my shooting. So I bought a Weaver 10X and put on the M700.
The scope can be important. You really want one that has a nice bright image. I'm not a scope expert but I know "similar" powered and sized (objective lens diameter and tube) scopes aren't equal just because of power and diameters. Some will give you much brighter, more detailed image. That's what you want. It's nice to be able to look back into the shadows under some brush, or a fence line, and see what's there vs. just seeing a dark area.
You mentioned your shooting skills. If you haven't been to an Appleseed, and you can find one in your area, you'll be amazed at what you can learn and how it will improve your shooting.