I am also looking to upgrade the brakes on my 95 ti. There are options for the front and very little for the rear. And the front - rear biased not sure what combination would be the best. I did find this link
https://srs-concept.com/product/e36-...e-adapter-kit/ it claims this adapter allows you to run z4 3.0i rear discs and 325i/328/Z4 rear calipers.