I thought the specs were pretty close. You should be able to handle a 9' mower and a 4x5 round baler with that tractor, about any of the more common brands anyway. Personally I would not try to step up larger than that. That mower on the Montana is plenty. I can run at a higher field speed (1 gear)with the MF 5455 because of the excess hp and get the same quality cut.
Last year when I was shopping for mowers, I priced Kuhns and then went down the road 10 miles and priced JD's(green painted Kuhn mowers). The JD's were somewhere over $500 higher.