My choice for the rack is the 924 - 944 rack. The reason is that it takes 110 psi from the pump.., and happens to be the same as the stock e28 pump. However.., I got lucky, I found a guy in Los Angels that had a bunch of 944s that he was parting and was able to get the rack, pump, mounts, and dual universal link, all for $100. Not bad.., not bad at all.
This evening I spent a few hours lining everything up so to weld on some mount tabs. Will post some more pics as I get further along. Your post has been of great help and will definitely same me time in the long run knowing in advance how to tackle certain conversion issues. Also a big thanks to Spongbob for great shots of his project.