I would pay someone to use a big tractor to finish mower the 11 acres. Bush hog then use a Finish mower to get it down to where it can be mowed. Then go buy a 60 inch Zero turn. You probably want a 60" to do 11+ acres. Hopefully the neighbors will let you use it on their lawns. You don't want to get too heavy and/or big of a mower for such small lawns. Maybe the 60" can be a back up for your JD?