Fiverr,
First what kind of mower are you thinking of pulling? Most all bush hogs are PTO driven and require either a 3 point lift or remote hydraulics to operate, meaning you have to have some way to spin the blades, and some way to lift it. Now, a "pull behind, self powered" mower would work, but the largest I've seen is around 5 maybe 6 feet for the cut. They attach to the tow vehicle, have their own adjustable height wheels and their own engine. I had a Bush Hog brand (GT42) I think that was nothing more than a pull behind lawn mower, although it did have a stout blade for tough grass. 42 inches is not much of a cut width.
14 acres, that'll take a while. I have about 8 acres of pasture that I mow with a 6 Rhino finishing mower set at 3 inches, it takes me around 4 - 5 hours to mow that.
To answer your question, depending on the steepness of your "rolling hills" just about any of the 4 wheel drives could handle it, but then again if it's "risky" on a tractor, may be risky on a utv also..
Good luck,
Roger