I'd like to make a small shop press from an electric motor, say 18'' tall max, with 6" of travel. It should be able to press say 10,000 psi and hold for several second or even maybe indefinitely. My question is two fold. First, what type of mechanical action would be best to turn circular motion to linear motion? A worm gear, toggle press, screw/servo, piston style press? Does it matter in terms of rigidity? How would you design such a rig?