I ended up getting the United box. I not sure of the model number right now. 6xxHD, something like that. It is a 6 foot box. I used it this a.m., seems like it will fill the bill for me.
I have not paid for it yet, I picked it up late on Friday and the dealer and I agreed to settle up Monday. He had quoted me $315, several weeks ago. If I am not mistaken this was for the 6 foot box.
Sound about right ?