Brake system Volvo V50 2.0D, BJ 03/2007

Hello, my moose will soon be due for the brakes. Now I ask myself, which brakes are the right ones?! I kept pushing on them: Suitable for 16″ rims but not for 17″. In the bill are entered 205/55R16 90V, raised are 205/55R17 93W. So the 16″ brake system (front 300mm, rear 280mm) should be present, or am I wrong? Could someone be so nice and enlighten me a little bit here. Thank you. EDIT: So, after I now have the brake caliper a I found the following: Brake disc at the front diameter 300mm, at the rear 280mm. But for me, the question still remains: What is it like with the rim sizes? Why are some discs, even if the diameters are the same, not suitable for 17″ rim size?