Well, here's my .02 worth.
Price -- I would not put a high-dollar scope on this rifle. Based on your description, this rifle is probably going to spend a lot of time bouncing around in a truck. I'd much rather beat up a $200 scope than a $1000 scope. And while the optics may not be as clear or bright, there are plenty of inexpensive scopes that are every bit as durable as the high dollar stuff.
Objective size -- as others have said, go as big as is practical without having to mount the scope so high as to not be able to get a good cheek weld for off-hand shooting. Depending on the barrel profile, you should be able to go somewhere between 42-50 mm.
Adjustable Objective -- go with side focus. So much faster than an AO it's not even comparable and depending on scope mounting height, can usually be used while supporting the rifle with the same hand. I've made myself a promise that any new scope I buy from now on will have side focus. It's so much of an improvement over an AO, that it's finding it's way into the low to medium priced optics.
Power -- My preference would be in the 6X-??X range. I've never had a shot at a coyote that needed anything less than 6X and had plenty of shots where the higher power sure was handy. The filed of view difference between 4X and 6X on the bottom side is almost negligible. About 2 ft. at 100 yards. Roughly 19' to 17'. Both more than enough to spot a coyote at 100+ yds. Top range depends on your choices for brand, price, objective size, etc. There are 6X18, 6X21, 6X24, ??.
Brand -- In the price range and power range that I am suggesting, I have the most experience with Simmons. I have had excellent luck with Simmons scopes. They are sometimes a bit sluggish while zeroing, but once set I have never had one come off zero and I've never had one fail. I have a Simmons 4X12X44 on my Remington 700 in 300 Win Mag. It's been on there for probably 25 years and still going strong. A Simmons scope meeting all of my requirements above can be had for around $150.00. For a bit more money, there are several other decent brands of scopes that fit my criteria. Millett, Mueller & Nikon to name a few. Only brands I personally will no longer consider (based on past personal experience or experience of friends) are Tasco, BSA, Sightron (decent scope but overpriced for the quality) & Barska .
Hoss