For NEW, I would be buying a Kuhn if I had your tractor... Get one sized with a gear box sized bigger than the pto hp of your tractor, and it should last a long long time!
For used, I have a REALLY GOOD Howard HR30, 80" wide, it's very HD and I'd make you a great deal on. It's ready to go and other than paint, it's in excellent shape!!
You'd have to ship it though...
SR