i would buy an e36 that is in running condition. then transfer the go-fast parts over to the new car. use this salvaged car as a donor to make the running car much faster...

word of warning... this could be very expensive as sorting out the proper components and tuning it will take lots of time and $$$$$$

yes, the engine will fit in an E30 chassis but will require work and custom parts. its been done too many times already...