The proper way to do a turbo engine is use a Crank from a 524 Turbo Diesel. Get custom Pistons from Ireland engineering and use forged rods. Stock rods bend when you get over 12 lbs of boost.

If you just want an engine check out LKQ- cophers U pull they have e30s there with engines. Tranmission, you will need to get one rebuilt. All the Autos I see for sale or junked are because the transmission is going OR the timing belt broke.