Sure, the Euro E36 M3 six speeds will bolt up to the engine. You'll need to fab a trans mount maybe, as i'm not sure if you can slide the stock one far enough back to accommodate it. You would also need to modify the driveshaft. You would also need to modify the shifter linkage. Also, I doubt there is room in the tunnel.
You could also do a unit off the S54 engined cars. Same issues as above and you'd also have to change the clutch disc.
Also, you could do a 330/Z4 six speed. But they are a cheaper unit but more compact. Probably easier to fit in the E30. I think you'd also have to change the whole clutch and flywheel do the 330 style stuff in addition to the issues above.
Either way it's a waste of time.