Size of Tubing and Heim joints for Traction Bars??

Basically Im just building a set of long bars like the Lightnings using Heim joints.

What would be a sufficient size....im thinking 1inch OD DOM tubing and 1/2 heim joints??????

Just would like to know before I go to the metal supply and pick up what I need.

when I finally do mine someday, I was thinking 1 1/4 or 1 1/2 DOM with 3/4 heims.
But my truck sees somewhat hard off road use, rather than just street.