People sure do like to spend your money, don't they? Fix the 8.250 up. It is plenty strong, bolts in right with no modifications and has plenty of aftermarket support for gears. It's a no brainer.
I agree, the more expensive and complicated the more likely most of these guys cars will sit up on blocks instead of out driving and having fun.
But if you do a lot of long trips the 8 3/4 has one advantage is easy gear swaps. My uncle had a pretty serious 340 duster back in the day but when we would go on camping trips he'd put in some 2.94 gears and tow the boat or the camper up north (340 don't make torque lol).
Most of the time it had 3.23 in but if he felt like racing he'd drop the the 4.10 and go looking for cars to beat.
P.S. his car is on blocks now lol didn't survive the last 340 build he was shooting for 500 hp but never got put back together.