I'll be doing a full brake job later this summer (calipers, rotors, SS lines). I have a sticking rear caliper that caused the rotor to get scored so I figured that while I have the system open, I should do the whole shootin match.

The only other upgrades I can think of to cure mushy brakes would be an aftermarket proportioning valve (adjustable) & maybe a better booster (but I have no idea what donor vehicle would work).

Another upgrade for better braking would be a drive shaft brake ... but you're looking at $$$ to get'r done. That's not an option for me though since it would install where I have the drive shaft quick disconnect installed.