Help on tires

I am taking delivery of a new 335is late this month. I upgraded to the 19" wheels and run flat tires. The 335is will be my daily driver in all seasons but winter. I will store for the winter. I am worried the ride with the 19" tires will be rough on the Midwestern Roads where I live.

I will not be tracking the car. I would like the car to preform well and have a reasonable ride.

Should I look at getting 18" wheels? If i go with 18" wheels should I find a set of the 313 in 18" or go with a non BMW Wheel? For the tires should I get tires that are not run flat?

bump