BR your bolt in roll bar is as nice as they come for a bolt in part. I wouldn't use that show bar above to highlight anything. That piece wouldn't pass tech with the way that the main hoop is bent. Your bolt in bar is safer than that one.
My personal material preference with all safety equipment is DOM mild steel. More and more organizations are requiring certs for post weld heat treatment on chromoly bars. Not very easy to do on a full cage!
