I have a 1996 328iA with 71K miles. It did not come with the sport package and has the 15 inch wheels. What does the sport suspension consist of, and where is the best place to purchase the parts. How many miles before the OEM shocks wear out. I do not want a harsh ride, just better handling. Will just changing to larger wheels and tires help or the suspension pieces. I am on a limited budget and prefer to change one thing at a time. Thanks