Yes. The hydraulic system may work for a single ram-assuming the helm has enough capacity and you don't mind the tug and slow steering. It's proably going to be slower than what you have now because the external ram is bigger. I'm pretty sure the system won't work for a dual ram application.
If you went with a dual ram system, you'd need a larger helm. Now you can go non boosted, which would eliminate the need for the supply and return lines (those other two lines to the helm) and the pump, but I'm guessing that it's going to be really stiff and slow. Some outboard fans proably can tell just how slow and stiff the system would be.