Your local tire shop can help you with this problem. Even though most tire chains like Tire Kingdom are rip-offs, they can tell you the tire/wheel combos which will work with your car... without any cost.
It sounds like you are looking for the tire/wheel combo which results in the largest sidewall size so that you will have the smoothest ride.
Tire sizes are written this way: Diameter of the wheel, width of the tread, percentage of the sidewall.
So, if the diameter of the wheel is 18 inches, and the width of the tread is 225 millimeters, and the sidewall is is 50%... it means that the "bead" of the tire is 18 inches in diameter, the width of the tread is 225 millimeters, and the sidewall is 50% of the tread width (in this case, the sidewall is 112.5 millimeters).
Your local tire shop can help you to figure out the wheel size, tire width, and sidewall size that will fit your vehicle, while providing the largest sidewall size.
That's written as (1) Diameter, (2) tread width, and (3) sidewall percentage.
A tire which is 18, 225, 50 means:
1) The diameter of the wheel is 18 inches
2) The tread width is 225 millimeters
3) The sidewall is 50% of the tread width.