I have NOS PTO's cheap and can help in sizing hydraulics if you need it. Also have a lead on some positive displacement pumps (but an active ebay, so PM me)....
....Have you researched prior threads about putting a plow valve on the 925? I'm wondering if it can take it's pressure from the tank side of the winch valve. In free flow, it has to have the volume that can go through it but the actual flow through a section (to your raise or turn functions) can be a very small flow rate.
As I see it, the plow raise is one function, with a blocked center to hold it up. No down pressure is needed, but the flow must relieve and go to tank for the down. Most plows have 2 single acting turn cylinders and that hooks up like a double acting cylinder with a and b ports, blocked in the center position.
Yeah, hydraulics are not my forte. I'd rather not have to change too much of the existing setup.
I seem to remember seeing a m925 install where someone ended up using a electric powered hydraulic unit for the lift function, due to not being able to hold the plow up with the trucks open center hydraulics and then used the trucks hydraulics for the angle cylinders.
My plow has two 4x20 double acting angle cylinders that are tee'd together and have a much more volume than the single acting 3x10 lift cylinder.
For a start I would love to find a direct replacement for my winch control vale that blocks the work ports while in the neutral position, yet still be compatible with the open center system.
I would think the winch would still function the same, while allowing me to hold my dump bed up without constant manipulation of the control lever.
I could then put quick-couplings on the hoses to the winch and use that to power my angle cylinders, and my electric unit to raise and lower the plow...