I went to the shop at lunch, it's nice having a race shop close by, and we decided not to decide. Yet anyway.
Going to get everything in first and do the doors last, easier to get in and out while putting the rest in.
I've gleaned over all my pictures and can find no real pattern. They're all different. From an Engineering and function standpoint "B" gets my vote, but I've never seen it done like that. Most runs a third parallel bar or a couple of short verticals between two parallels. Some don't even tie the door bar on to the downtube at the forward tube making a weak link where it ties into the downtube.