If the ground is rough as you say it is and you'll be in the seat for long periods, get the air ride. I have air rides in my dumptruck and my backhoe. The difference is substantial. The older you get, the more your back hurts. The air ride is infinitely adjustable. Typical suspension seats have "gaps" between adjustments that might not fit your weight just right.
Don't ever let anyone tell you comfort is for "softies". Comfort is for smart operators who don't like feeling beat-up when they get off their equipment after a long day of seat time.
Another air ride benefit is better resale value. Heck, you might like the mid-PTO. Never know, someday you might want a power broom, snowblower, etc.