I also sit while turning. I use an old office chair with wheels. I have my Jet mini set up on the base unit(Leg unit, base, call it what you want) set at it's lowest height, while the chair is at it's highest height. My lathe is set at a right angle to the wall, and about 2 feet from the wall for when I try to turn a bowl or something that requires me to be at the end of the lathe.
I wish I had some pictures, but if you saw me you'd know why I don't have any...[
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Hope this helps, and take care of your back (from 1 bad back person to another)
Jim