This is the Sigma GE setup for 1000 that D did.
229mm solid disks
sigma calipers and caliper bracket
1200 coupe or 120Y hubs
1000 lines
1000 coupe or other later twin system master cylinder





Or you could just put 120Y or 1200 disks, hubs and calipers.

Or this hybrid that Jempson did,

Late model 120Y (1975ish) hubs and disc's (219mm diameter) which bolt straight onto the 1000 stub axles. Then get a GE Chrysler Sigma (the sigma with fake air vents on the gaurds), grab the calipers and caliper mounts, re-drill the caliper mounts to suit the 1000 stub axles (using the old drum brake as a template). Machine 2 mm off the heads of the 4 bolts that hold the caliper mount onto the stub axles, then assemble.

This is the Laser setup from Dattoman1000 on Beatties car.






and Dattoman1000s custom hub and caliper mounting plate.