Finished the hoops today, hung a center purlin just to aid in leveling the hoops and trying to get everything leveled out.
Its not perfect, but its not looking bad to me so far. I need to figure out my end hoop bracing and the best way to get them squared up. I cut 5' lengths of 3/4"x1/4" steel I had and drilled holes in each end, I think these might work ok to brace the end hoops, from the bottom of the 2nd brace to up on the end braces.
I'll have to think about what the next steps will be, I will probably work on it more tommorrow!