New late spec 316lux owner needs engine swope advice

[delux]

Hi there brand new to the world of bmw really love the e30 shape been reading up on them, got a really fantastic condition 91' 316 i lux thought it wud be perfect base for a nice engine swope, so would love everyones inputt on which is the simplest 6 cylinder to put in it, i fancy a 24v 2.8 from crappy e36 and i like the 3.0 and 3.5 from e28s im assuming i need gear box from the 5 and 325i engine mounts etc but e30 diff is best to use LSD wise

cheers folks