I was looking at rebuilding my rack & almost pulled the trigger. However, I was told that it takes some very special tools, and since the thing is under immense pressure, ANY scoring of any sealing surfaces would lead to very rapid failure.
I snagged a 1997 Z3 1.9L rack for $220 shipped form
http://www.car-part.com last year. Shipping will be more to HI, but trust me, it is cheaper & easier to find a used one. E30 racks blow ass anyway, they are flimsy.