It's really not that bad. However, the EWS stuff and other electonic gadgets will take some wizardry. It can be done, I'm sure. I would stick with the E36 era engines though. That's just me. I'm going to go with a '95 M3 (OBD I) engine so that I won't have to deal with the extra electronics.
'86 325es (TURTL3): PJ peetsa hawler
'87 535is (BADWATER): almost done... really.
'86 325e (GRN HLL): DD/show/rocket
'04 x3 3.0i: Wife's Bimmer (manual, woot!) My BMW Blog