As a quick follow up to the talk on the Sway bars. I attached a sheet showing the roll rates. I suggest using the 1¼" or 1½" spline bars because the POLY mounts for these sizes are the most common on the market. If you go bigger you may to re-think the mounting procedure.

UPDATE:
Hellwig has agreed to supply a bar for this build. It will be an 1 1/4" hollow tube. Makes 690 lb/". This still may be a bit light for what I need, but it will work perfect for most applications.