Changing from 5x4 to 5x4.5

What rear axle size are you running now? If 8 3/4, swap shafts and drums, If 7¼, an axle from a 73 or later disc brake car is a direct swap. You can also look for an 8¼ axle with a 4½ bolt pattern, but you'll need a shorter drive shaft as well as U-bolts and pads for a 3" axle tube. Same drill if you land an 8 3/4 axle.
For the front, find a 73 or later disk brake set up. This includes UCA, spindle, rotor, bearings, caliper, ball joints, and hose. Swap the master cylinder and brake proportioning valve, too. Recommend that you save shipping and buy new rotors locally. (or get some of those slotted and drilled jobs.)