It would be helpful to know where you are at in the world and the lay of your land. As AKFish pointed out, your hay crop will make a difference.
Here in the hilly northeast, I would say you are a little light on HP and possibly weight. A 5425 or 5525 would be a really good fit for your needs around here. My mower in first cutting can put a pretty good load on the tractor. Traction is not a problem with this light of a tractor due to the addition of 4x4. I have added fluid to the rears, 2 wheel weights per side for the FEL and this also helps prevent pushing when baling on hillsides.