It kind of depends on how much manure you have to move. One horse or fifty cows and calves. We used a little new holland 356 (i think that's the number) twowheel spreader for years. a smaller 45 horse tractor pulled it easily but it took a long time to clean out a large pile (a week) and we didn't always spend the time to get manure to the back of the place. Last year I came across a huge tandem axle real cheap (800) and grabbed it. Takes a big tractor which was here and has cut down our time spreading tremendously ( couple days), now the crap makes it to the back end where it was sorely needed with days to spare. So it boils down to how good a deal you can find since you're not using it all year and how much time you have to spend doing it. I say buy the biggest you can afford and pull and you won't regret it.