I have a perfect running ac unit out of a 93 BMW 318iS. I'm not too sure if it would set up in an E30, so please check first for your sake. I also have the lines and evaporator unit, will sell all together for $75 or just the compressor and belt for $50.
The unit works great, I only took it out because I am building a turbo kit on the car and it is a lot easier without the ac inplace.