Welcome and congrats on the pending arrival
I'm a similar situation: car-loving Z4 owner, but pending the arrival of our first child in November I sold my Z4 in May and picked up an e90 replacement (at Kinross auction funnily enough). I didn't want to give up my Z4 but common sense must prevail at times - at least you're heading in a direction looking at e90post
Personal preference but I prefer the M Sport front end over the SE with aero. No idea where you could source one though other than the usual auction sites or possibly on here. Not sure if that breakers yard at Inverkeithing is still there? Might be worth a look.