looking to turbo e12 m30

[BMWe30Mstyle]

Have a very nice 78 530i, 78,000 orginal miles that we will begin giving attention to soon. Driveshaft mount bearing is first to fix then some suspension tightening. Future plans would be looking into a turbo induction setup. I have not read a lot about the e12 turbo setups and would like to get some sizing and direction keeping the stock drivetrain. Any links or used parts are +++++ thanks!