You will need to decide how many valves you want, probably two minimum and possibly three or more. You will need to figure out how to mount the valve, probably on the ROPS if you have one. I would not pursue an old valve.
Then you will need to get the cylinders to fit your tractor. For these I recommend you get Fit Rite Hydraulics to make them. In fact, that is who I brought the whole system from (valve, mount and cylinders)
Manufacturers of tractor 3 point hitch top and tilt hydraulic kits, hydraulic top links and hydraulic side links.
www.fitritehydraulics.com
Then you will need a few new hoses probably.