What size would you recommend?
Cylinder diameter, rod diameter and pressure?
Pressure does not matter.
The important parameters are retracted length, bore, stroke, and to a lesser degree rod diameter. I recommend getting one with a DPOCV.
The one on my L3901 is 2" bore, 20" retracted, 10" stroke, and 1.25" rod. Works well for all of my stuff.
Dan