For top of the line look at Diamond and Bradco ($9-10k), for a good mower at about half the pricetag CID has a few good options. I own a Diamond and a CID and have been happy with both. The Bobcat brand brushcat is good for pasture as long as the ground is firm and not too sandy, if it's sift the rollers tend to push up dirt in my experience. You also can't tilt or raise the mower to deal with the bigger stuff. I live in SC where things are pretty sandy.
It will tax your hydro cooling system so make sure it's up for the task.
It will tax your hydro cooling system so make sure it's up for the task.