Update time.
Car will be going for a full GTechniq detail soon - 2 stage machine polish and the Crystal Serum Ultra Black package.
In the mean time I have now bought some wheels for the build - OEM F80 437m.
Intially I am going to try them on with the OEM tyre sizes (255/35 front and 275/35 rear) but my car also will be getting lowered soon on the H&R springs that I bought, so at that point I will have to change the tyres as they will will no doubt rub once lowered!
Once the springs are on I'll probably go for either 225/40 front and 255/35 rear OR 235/40 front and 265/35 rear.