Addco used to have sway bars for these cars but they aren't listed anymore in their online catalog, you may be able to find used ones somewhere. There may be other sources, or parts from other cars that can be adapted. If you use the search function you should be able to find older discussions on this topic.
As for disc brakes the setup from a 1968 through 1970 big car will work but they are going to be hard to find, especially in usable condition. 1971 and newer was a totally different setup. You're better off going with an aftermarket setup. Master Power has a kit:
https://www.mpbrakes.com/product-cat...ville-1966.asp I thought Scarebird had a kit as well but it doesn't show up in their catalog; however Scarebird is a member here and can provide more information.
https://scarebird.com/index.php?rout...tegory&path=63