so call me stupid but could you use a cheap hydro cylinder and the stock pump for full hydraulic steering?? use the existing pluming on the pump and run hoses into a hyraulic ram?
most of your questions should be taken care of there.
And you'll need a bit more then just a ram and your pump. You'll also need an orbital valve that will direct the flow of the fluid. Or else you'd only get one way of action.
But yes, you can use a $50 ram and a cheap-o power steering pump, its the orbital where things start getting expensive, as well as fittings and lines. But read up on that link, it will lay out everything you need.