For your stated use case you should first improve the brakes and suspension. Later style disc brakes with quality pads are more than enough, or spend the big dollars and get a kit from one of the usual suspects.
The problem becomes the "while you're in there" mentality. While you have the front end all apart for the brake upgrade, why not just swap to 1.03" torsion bars? And why not add a front sway bar? And of course you would be replacing all your bushings.
Here's an unpopular opinion: I would not worry about the 7.25 diff right now. If you don't hammer on it you'll be fine. If you do hammer on it you'll soon break it, but that just means you've found your next upgrade. There's no reason you can't do the front brakes and suspension then upgrade the rear later, just get a couple of BBP rallye wheels for the front until you can swap out the diff.