Issues with my 2001 F-250 7.3L transmission continue...

I will say it again and I speak from experience; with the weight you are towing I wouldn't go with anything but a BTS or John Wood. I know you are limited on funds but you will be doing this again down the road with any other tranny. You might get 100,000mi warranties but that doesn't do you any good if it breaks down 60 miles from the nearest town. If you were towing lighter that would make sense, but given your situation, spend the extra money and do it right the first and last time.