I can only help you on the color , AW all the way. The best looking E90 I have seen so far are AW and Artic. You will be surprise to find out the high flexibility to mod a white car e.g. gunmental rims only look great on white cars. Since this is the color you always wanted, forget about space grey, a new color only look fresh to someone for the first 6 months.
About active steering, I have given up telling people how great it is (I have it). There is 90% chance you won't get it because you will not pay for something you don't have a clue what it really is. Once you started to ask around in any bimmer forums about Active Steering, you will still end up with lots of confusions because no matters how great AS some users have said it, there are still a lot of people who will go againts AS e.g. 'you are not in control the steer'
. Test drives both? might help or might not help because everybody has a different driving style and cars ownerships history.
Best of luck, welcome to e90post , this is a great family for 3 series fans all over the world.