what would be better for clearing 8' rows. They both look easy to use, which one beats the tractor up less.
You probably will not find a hydraulic drive 8' mower. With hydro drive up front you obviously cut the material before you run over it. You mentioned only cutting grass so you'd have no problems with a 8' PTO mower.
With a rear mower I mow anything the front axle/bucket will push over.