Swapping rear end question

this is kinda where I was headed.. O:) the $$ you save on the 8.25 will be spent on other things to get it done correctly - do the 8.75 - overall an easier swap and you'll be ahead on value when you get to the other end.. some may argue that the 8.25 is "strong enough" - - I believe the 8.75 was a performance upgrade option for a reason... JMHO.
personally i'd spend the extra and go with the 8 3/4. when you are ready for a better set of gears and a sure grip ya just change the center section..

both you'll have to shorten the drive shaft for anyway.