You can use Bosch, Denso, AC DELCO platinum spark plug. You do not have to change ignition coil but when you remove the coil then note that which coil goes to which plug with a marker or some tape so the coils and plugs are not mixed up. Replacement of the spark plugs must be a part of the routine maintenance of your BMW
328i. If you change spark plugs on regular time intervals then your car mileage will constant.