Hayden, I think that most square balers weigh in at around 3000 to 3500 lbs, so I think that you are probably in the ballpark of how large a tractor is required. I really think that Doc has hit it on the head when he said that it is just a matter of safety and of wear on the tractor. The weight and HP requirements of a baler are pretty high, so to be safe, a larger tractor is often better. I think that you could certainly square bale with your tractor, perhaps the MoCo is out, but you could certainly cut it with a disc cutter or sicklebar, and then rake it into rows. You might want to consider working with someone local who does custom baling and you could cut and rake and let him bale, just to get the feel for how things work. Haying equipment is also pretty darn expensive to buy and maintain for cutting only 25 acres too, so you might also want to check out the economics of it. You might just want to talk to some local custom hay balers, and see about cutting the hay on shares. Most balers around here will do it, and if you were to cut and rake it, the share they would take to bale it would probably only be about 1/4 of your hay.
Having said that, if you really want to do it yourself, you might try to find out if any other people in your area have similar haying needs, and try to do either baling for them with your equipment or to do some type of a cooperative purchase.
p.s. I think that with my loaded tires and the loader on the front (which I never take off) my 5520 weighs in at around 8000 lbs. My comment was not meant to offend anyone about their tractor not being capable, just trying to impress upon people that the demands of running haying equipment on a tractor are pretty high, and that there really is a good reason that the hay farmers do not bale with 20-50HP tractors. Believe me, if a $35,000 tractor worked just as well as the $60,000 tractors they use, I bet most of them would be using the cheaper ones. The primary reason they use these larger Ag tractors is that it is safer, and the smaller tractors will just not hold up to the heavy demands that the haying equipment requires. (Also gives them something to show off at the feed store/w3tcompact/icons/laugh.gif) Perhaps if you have a chance, you could arrange to take your tractor to a dealer, and try out running a square baler behind, and see what you think. It all depends on your level of comfort, and how you feel it might affect the longevity of your tractor.
I hope not to deter you from wanting to cut and bale hay, but rather to make sure that everyone stays safe and that both you and your tractor are around a good long while.
