I have Gaz Gold on my Sapph and there's a hairs breadth between the front inside tyre walls and the struts - it's very tight - and that's on standard wheels and R888 tyres. They also rub a little on the inside of the rear turrets but I've ignored that.

I think Konis or similar springs and adjustable dampers is a better option than coilovers - lighter and they fit without rubbing. Coilovers make sense if you want to change the springs, ride height and damper settings - maybe for track use.

Charlie