if u change ur brakes , it wont dust up anymore, its because you need new pads, thats why the wheels are dusting up crazy fast.
change your pads ( rotors too if needed ) and then see if it still dust up , guranteed it wont dust up as much.
If you want some 17" rims get some M3 rims from the E36 M3s , they are alot cheaper than BBS rims ( if u got the money get BBS rims ) and looks very good on stock E36s.
DSIIs DSIs and the 5 stars or even M contours.
if this is your first RWD car, then it will be safer for you to get some winter tires..make a huge difference in winter handling and braking.
and lastly , im not too sure on the 318 fuel, ive only owned E36 328s.