Make a custom strut housing out of the e36 strut, use the e30 shock cartridge, and put in said coilover sleeve ie. Ground Control. And match the spring rate to the e30, not the e36, as those are generally stiffer.
Will a regular e36 coilover fit? Not sure. Is the shock length the same? Spring rate? How about the top strut mount? Will it fit the e30?