Just a note on rebuilding - I thought I was up to the job - got the rebuild kit - even bought a cheap wrecker rack so that I wouldn't risk being stranded. Anyway, taking the rack apart is a fiddly job that you really need precision tools to do correctly. The problem is that by messing around with the rack on your garage floor or shop table you are going to inevitably hit, scratch or scuff the main rack piston - especially around the tie rods. If your scratch it, the rack is toast and will leak.
What's the point - you spend $80 on a new seal kit and the rack leaks again? I have had no luck with factory rebuilds either - my last one was good for 18 months and then gave up the ghost ($600 down the drain). The reality is that the OEM rack is garbage.
Now I just run it old school - no power steering.
Anyway to get the e36 rack to fit you need spacers on the mounting point and you need to make a frankenstein u-joint for the steering column (part e30, part e36). Zionsville sells it as a kit -
http://www.zionsvilleautosport.com/store/screen/prod/store_code/6134/product_code/E30SRC.htm