I need to tell you that if you were to use a single power steering pump with 2 returns when you operate the plow lift cylinder you will loose power steering. Here is why, the hydro boost valve for the brakes has a lot going on inside so you always have power brakes and power steering. The brake booster only uses a very small volume of pressurized oil to operate. It is a flow through system that also has an accumulator. You can see the small cylinder on the back of the booster. With the engine shut off there is enough stored pressurized oil for a couple brake applications. If you are steering fast and use all the available pressurized oil from the pump the accumulator fills the gap for the brakes. The valving going on in the hydro boost is more complicated than you might think. So using 2 power steering pumps will work fine as @75Monza has one for his plow lift. My brother's old plow truck was set up with an extra pump for the plow.