bro lowboosting,most of us here dont do the engine swap ourselves we send it to workshops for these kind of conversions to be carried out,so we might not be able to answer most of your questions in depth.
but basically its like this,get a half cut from which ever relevant jz series,secondly get the jz series into the engine bay of bimmer,third u'll need to fabricate the mountings for the jz series engine to be mounted onto the original bimmer cross member mounting,as for the shifter placement i guess the e34s & e36s should be just nice,i've seen a few e34s and e36s which is done up very neatly,and as for the wiring,well can't help u here cos i've got zero knowledge on this.