1. Enjoy car and wait until your fenders are already rusty from age
2. Do whatever to make the wheels fit
3. Refinish/paint fenders
Unless you know what you are doing or you plan to pay a premium, don't do this and plan to have your fenders come out nicely. There is absolutely no way you will not disturb the integrity of your paint by stretching and bending the surface it is adhered to, even if it looks like you haven't!
Do not ever shave your fenders unless you have a very clearly thought out reason to. Shaved fenders loose their structure very easily and will be prone to bending/warping, even under normal conditions.