Does a rolling mill and a hydraulic press do the same thing? Which one is more versatile or are both needed in a shop. thanks

You don't HAVE to use either. They are really de-luxe additions to a workshop rather than essential.

What he said.

A hydraulic press is more versatile- a rolling mill is really only going to be good for billets and stepping down to pre-forge a taper. A hydraulic press has more room to maneuver and the possibility of making dies for specialized work. Sometime in the next year I hope to make a press to facilitate damascus work and the odd sculpture, but for now a cheap and effective alternative is a sturdy treadle hammer.