I need to step the car up with some "proper" wheels and tires.

Going to run Dunlop Formulae R but the question is what size rim?
If I go 17" to lower the gearing that’s fine but what about offset?

What is the standard offset and what do you recommend or run yourselves?

I don’t need to comply with any regulations covering wheels and on our tracks here dont reach anything over 230 KMH.

All thoughts and suggestions are welcome and encouraged.

Size type et al let me have it.

TIA,
Hugo