I was in the same place about 18 months ago, what I did was bought a stripped lower for 75.00, a lower parts kitfor 70, and an ace skeleton stock for 70, the book by Walt Kulek "The ar-15 complete assembly guide vol 2. Ordered the completed RRA coyote rifle upper from them for 575, and for 740.00 I had a very good shoot Ar,...the only difference is the trigger single stage, vs rra two stage and the winter trigger guard. I plan on updating the trigger in the future.
I but the savings into optics vs buying a complete rifle for 1200.00
If you are mechanically inclined at all it really isn't difficult especially with the book to guide you.
By only comment about the coyote rifle vs coyote carbine is the 20" rifle is barrel heavy, balancing point is in the front of the gun,...the other issue I've had is using a tactical sling over the shoulder under the opposite arm with the 20" barrel If I kneel down to look at sign/tracks I have to be careful not to jam the barrel into the ground/dirt/snow
I'm working on my second one now it is a 6 position collabsible stock and I'm leaning towards the RRA ATH carbine for that which is 3/4 of a pound litgher, has a shorter 18" barrel.
Either will meet your needs,...I would think about how are you going to use it, coyote hunting
in cover calling, or target/ pd shooting esentially off a bench? How far will you be carrying it on a outing?