Pretty tough to find an uncracked dash, but you can have yours restored, by Just Dashes, for example. I have one in my '85, and ut looks perfect, and is supposed to last longer than an OEM part. Expect to pay $2200 and wait a few months, though.
The SLS can be repaired, but many owners just pull the system off and install Bilstein HD shocks at all 4 corners, along with some aftermarket springs, such as those from Bavarian Auto.
If you haven't already done so, go to bigcoupe.com, which is the best site for all thing related to the 6-series cars, and the E24 forum on bimmerforums.com is great, too. Far more active than bimmerfest.