Here in the northeast,one of the biggest factors is how well can it cold start.......its a huge issue here,although diesels are much better than they used to be.My tractor sits in a barn in the winter with no running water and no electric,so it needs to fire on its own even down to -20 degrees,which it does every time.Not bad for a 24 yr old ford 1910.Some tractors will not....
Personally id go with the 35hp pto,because i have 28.5 and often wish for a few more..but im taking care of a lot more property .For what your doing,either will be fine running the impliments you have.
As for the PTO rpm,while it is important,it isnt the end all.Most small tractors run 2500-2800rpm pto speeds...The piston speed is more important than the RPM,IMO. IMO with diesel tractors, it is always better to rev it too high than not high enough,the only thing you stand to lose is a little extra fuel,an engine thats lugged and labored constantly will wear out much faster,as the load is higher,and the pistons thrust side and bearings take a a pounding.A larger engine may spin only 2000RPM,but have a higher piston speed than one running at 2500,due to a very long stroke.These long stroke engines make great torque down low,but they are usually heavy,expensive and rpm limited.There found in larger tractors usually.Shorter stroke small diesels spin faster and run more like a gasoline. engine .I am a fan of the long stroke low rpm diesels in most aplications.....
