Guys,
If anyone is interested I have CAD drawings for the brackets required to undertake the rear disc conversion on an AMC 20 axle, there are two options
1. Suzuki Vitara (early solid disc 290mm x 10mm) and Nissan 300zx (R31) calipers or
2. Suzuki Vitara (early solid disc 290mm x 10mm) and Nissan Maxima (A32) calipers
I'm using these designs to fab up my brackets for my D44 (obviously different attachment design to the axle), I'm going with option 2 as I found the Maxima caliper easier to source. Both options have handbrake capability. Grab the cables as well as they are long enough to connect into the original Jeep center cable. In theory this is pretty much a bolt on deal once the calipers and discs are sourced. The brake fitting is M10x1 but adapters are easy to come by. My total cost so far including discs/calipers/caliper rebuild kit and brake fittings is well under 100 GBP.