305-45-17 tires on Pony wheels (17")?

So my new coupe project came with a set of 17x9" Cobra wheels (03/04 style) with 245-45-17 front and 305-45-17 rear tires (ET Street R).
I want to put a set of 17" ponys on the car.
I know the front tires fit perfectly with a 17x8" wheel.

My question is should I run the 9" wheel to get the backspacing to clear the 305-45-17 tire properly?
I don't want it to stick out any.
Looking at the 10" it puts the outer edge to close to the fender for my liking.

The cobra wheels I had on it the fitment was really good. I just don't like that look on a foxbody.
Couple pics below for reference.




Thanks,
Ryan

I already have the 305's and they are like new, so buying another size isn't an option at this time.
Car already has 9" wheels and the tire fits fine, I just don't like the cobra wheel on a fox and am looking at a set of pony wheels.
Just curious if anyone has pictures of that tire on a 9 or 10" wheel on a fox?