So a trip to Home Depot resulted in some 1/2" black pipe. Only need to get some hooks mounted still to hang the pans.
I couldn't get a good pic with the rack standing, so laid it out on the ground.
The legs are 12" long on each side of the tee.
The posts are 6'.
The cross pipe is 4' between the tees, with a 6" piece on the outside of the tee.
It seems pretty strong. I did a few pull ups on it and it held up, so should be just fine for the cast iron.