It was not cheap, but it is worth every penny. I turn a lot of furniture parts which means I am often spinning wood that is not centered on the lathe. This monster does not vibrate or bounce at all. The downside however, is that the headstock by itself weighs over 150 pounds. The whole unit clocks in at just over 600 pounds.
BamaBoy, research bow lathes and treadle lathes. You are skilled enough to make one and it will do whatever you need. If it doesn't you will know how to make a bigger one that will. They were mostly made of wood - even the bearings (some used tallow and leather). I am willing to bet that you can find free plans and modify for your specific needs.
As long as what you are planning to turn is symmetrical, you do not need to worry much about weight. I learned turning on a homemade lathe that was made with a washing machine motor and a couple of pillow bearings mounted to blocks and thumb screwed to a 2 X 12. Only if you are going to do any off-center turning (the foot pads on Cabriole legs, legs for a Federal style high table, bowls made from green wood, those types of projects) do you need to worry about having a lathe that is heavy enough to dampen the vibration.
I have one I am about to sell. It was my brothers. It's Harbor Freight. Not great quality but he used it for turning pens. The tools I bought him cost a whole lot more than the lathe. I'm going to sell it for $100 as it is like new. The only problem there is shipping.
I think he needs more than 18 inches between centers.
I have seen some old wooden wood lathes where the only metal parts were the drive head and the tail stock center.
I have seen bow lathes - they alternate directions but still turn nice projects out. The treadle lathes are reversible but only turn the direction in which they are started.they are not real complex to build but it would take a craftsman to do it and make it look good.