I would recommend doing 225/45/17; Here is my logic:
Your current stock wheel is likely to be heavy and increasing tire width may exceed the recommended 225 tire’s profile due to the stock rim that could be too narrow. Furthermore, putting the wider tire on will increase your unsprung due to a heavier tire than the 205.
If budget allows, you can get a new set of 17" that is probably lighter than the stock 16" and you can choose the correct rim width that is good for the 225 profile. You will likely save on unsprung with a 225/45-17" on a lighter wheel over the 225/50-16" on stock wheel. In other words, your upgrade will not only made your car look better, your car will also have an actual performance gain due to lower unsprung. Two birds with one stone.