I did this a few years ago and sourcing parts is quite easy and it's quite simple to do yourself. Pistons, seals, dust covers etc.
Here's my post of the time with pics etc. of how I did it and one of mine was VERY stuck!

I used: Power Track Brakes for most parts.

While you're at it change the brake flexible pipes too.

Last edited by Richard - Aus; 27/08/16 12:10 AM.
Richard
1976 4/4 4 Seater