J Tiers gives the general guideline: height such that your forearm is horizontal when turning the carriage handwheel. It wouldn't hurt to build in a little height adjustment in case experience suggests that something different would be better for you, personally.
I've got my South Bend 10K on a wood bench, top made of 2 layers of 3/4" plywood laminated together, 4x4 legs, 1/4" plywood across the legs and back. It's solid, but in retrospect I think I might opt for a metal stand, at least for the legs. Not sure, but I might. Unistrut might be an option.
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Everybody is ignorant, only on different subjects. -- Will Rogers
There are lots of people who mistake their imagination for their memory. - Josh Billings
Law of Logical Argument - Anything is possible if you don't know what you are talking about.