I dont know anything about the grass/weeds/field foliage in OK but here the wife wore out the zero turn mower in 5 yrs trying to mow approx 6 of our 40 acres. Even our compact works its azz off to handle same acreage with brush hog.
I would second BG recommendation on compact. Turf tires can be mounted to avoid tearing up ground.
Tractor Supply and Murdochs both run good sales on safes a few times a year. I would have purchased from one or the other had I not got a screaming deal from a member here.