OK, here's what I don't get. Why is it so much more to buy an assembled unit than to buy the pieces? Just looking at Surplus Center, I see that you can get a 9.74 ci motor with a splined shaft rated at 20.8 HP continuous for $225(
Surplus Center - 9.74 cu in VON RUDEN MLHS160S4A HYD MOTOR .
A PTO mount pump that's 9.9 ci and rated for 21 gpm and 32 HP is $526(
Surplus Center - 9.9 CU IN PRINCE HC-PTO-1AC PTO PUMP CI 540 RPM).
A 25 gallon reservoir is $227 (
Surplus Center - 25 GALLON HYDRAULIC RESERVOIR)
Allow another $500 for hoses, fittings and a valve and you're out the door under $1500. With the pump and the motor having the same displacement you don't even really need a valve, they will spin at the same rate and you control the motor by controlling the PTO.
Am I missing something?
By the way I think this is a great idea and it's something I've given some thought to in the past.
* I realize this is only rated for 474 RPM continuous, 563 intermittent, so it's not quite right for this application, I just picked it as a quick illustration of what's available.