After considerable reflection, I decided to replace the original rails and bows from my earlier post with a custom made steel rack. My biggest concern was dynamic stress. The tent weighs 230 pounds and there was quite a bit of horizontal movement. If I had to make a sudden stop, I would not be confident the rails would hold under that kind of stress. Thankfully, I recently met a welder who really understood my needs. I will be posting pics in a build thread soon.