Ride on Fence line mower.

I’m looking for a mower to cut fence line prior to bush hogging. This would be for my wife who is resistant to zero turn steering. We used a Troy built steering wheel zero turn but it has seen better days. I have 5425 JD tractor with a Howse bush hog. I also have a Dixie chopper with 40 hp motor, a 6x6 Polaris and a Mahindra Roxor. She would prefer a dedicated mower; possibly with attachment. We have about 100 fenced acres which is also cross-fenced for cows.