Welcome to TBN, I do not see why you could not hook up the plow angle hydraulics to the rear remote hydraulics, You probably could also hook them to the loader control valve, but I would not because it would limit the versatility of your plow setup, assuming you are attaching the plow to the quick attach plate where the bucket fastens to the loader. By using one of these , without the use of an expensive hydraulic diverter valve, you would either have to use the lifting or curling circuit while you had the plow hooked up to make it angle, theraby losing whatever function you tapped into. I would probably just plumb another 3 way open center hyd valve with a spring center into the loader control valve, to do this, find the port on the loader valve with a T cast above it, this is your tank [or return port]. Plumb the tank port on the loader valve to the supply or so called inlet port on your new valve. Now take the original hose that you disconnected from the tank port and hook this to the tank or outlet port on your new valve. Now run your other two hoses to your left and right angle cylinders, and presto, you have just added a valve. As far as fittings, I found most of mine at tractor supply, as well as the hyd. hoses when I built the grapple for my Farmtrac 270. The main thing to remember when customizing an open center hyd. system is that the hyd oil is constantly circuilating through all the valves, even when you are not using any of the hydraulics, the fluid is sucked out of the resivoire, goes through the pump to all respective valves, through the valves unrestricted to the outlet port where it returns to the resivoire. It is when you activate a valve [move a lever] that you close off the tank port, and capture or divert the fluid to a work port , [hyd cylinder etc.] until either you release the valve or the pressure builds to the point that it opens the hyd press. releif valve, which overides the work port and diverts some of the hyd. press back to the tank in an effort to control max hyd. pressure. One last thing, do not fool with any hoses or valves with the engine running, high pressure hyd oil can cut flesh like a knife, some hoses are dangerous any time the engine is running, some arent, if you dont know which ones are and arent, assume they all are. good luck
