Busa I have considered using an Air/Hydraulic Power unit, what make did you buy and what is it's working Pressure
The air/hydraulic pump I'm using is a Sealey, output max is 10,000psi but can be regulated by varying the air input pressure, manual states ratio of 100:1 out/in.
I believe that air/hydraulic pumps are available as 10,000psi or 3,000psi versions, the 3,000 delivers fluid quicker as the pump has a larger delivery piston.
I don't know the diameter of the ram offered by JD2 but they state that the model 3 bender that I have, when fitted with their ram, will bend 1.5" solid round stock at 3,100 psi and 1.75" dia x .095 tube at 800 psi
hope this helps.