I dont see how you can go wrong with a Ford 9 inch. They are plentiful, cheap, and alot easier to change gear ratio's. Bucu bunches of after market parts are ava. All kinds of width selections.
I never heard the statement about the Ford rear takes away power? If it does it couldnt be very much.
The Dana is a very stout rear but that sucker weighs almost 100 lbs. more then a 9 inch Ford!! Changing gears in the Dana is not a easy task. You dont have nearly the slection of after market parts ( disc brakes,etc. ) as you do with the Ford.
Both reaends will handle 700 lbs. of torque with no problem.
Just my thoughts