25 acres is quite a bit to disk, especially with a tractor of that size. That doesn't mean it is impossible, but you will be working on it for awhile. My concern for you is that you're talking about disking infrequently. Depending on your time frame, and the conditions, you may struggle too much to do a thorough job with something light as you will need. Going smaller but denser seems wise to me. The 3 point disks for compact tractors are light compared to the drawbar pulled wheel disks of roughly the same cutting width.
For example, Monroe's nicely built 5 1/2 foot 3 point disk has 16 blades and weighs in at 606 pounds, markedly heavier than the cheaper angle iron framed versions. Their 6 foot offset wheel disk, by contrast, also has 16 blades, cuts only 6 inches more, but weighs in at 2935 lbs. In other words, what the 3 point disk would weigh with your tractor and loader on top of it, and then some, probably. For cutting rough pasture, hard soil, or other applications, it's no contest between the two. Once cut in, though, it could be maintained with a lighter disk.
A lot depends on the condition and circumstances, really. Others, with different experiences and perceptions, will have equally valid input that may differ significantly from mine, but I think compact tractors do ground engagement activities better with implements on the smaller side rather than larger. A smaller disk, say, can either cut deeper or go faster than a bigger disk, something I find more versatile than an implement of larger size.
I would suggest something in the 4 foot range that you can ballast as needed, rather than getting something bigger that you cannot pull if cutting deeply. Cutting through vegetation will take the heaviest disk you can manage, with most pounds per disk you can. If you're set on doing it all, you might strongly consider running over the area with box blade rippers first, then disking, even
though it means two passes. A better bet will be to hire it done first, then maintain it with your 7610.
If your ground is fairly soft and light, and not overgrown with sod, you can get away with smaller equipment from the get-go. If you are wanting to cut into old pasture land with a 6 foot disk behind that tractor, you're going to be hating life soon, in my opinion.