For the hoses just go to a farm equipment dealer with a sample of what you need the ends to look like. I have made up ends for fuel line, air brakes and more for guys. If I had the fittings and the hose I would do it an dnot much goes over 3,000 psi. As for the couplers, I would discourage that as you will lose fluid everytime you disconnect them and it will be such a pain, while you could easily install a valve that would handle your direction along with the line moving. As for using steering pumps I do not know what the operating pressures are on them if it would be enough for you, but I have seen old Dodge Snowmasters? that hade two extra power steering pums on them to operate the snow plow.
Troy