I second not going with the 16". Tire selection is not good. The main issue is the rears. Getting a tire in the width that most of us are looking for leaves us with little choice in the 15/16" size. I am not aware of any one trying say 16 on the front and 17 on the rear. I do not know how that would look. Any one that says that their 15" tires handle great on their Cobra has never driven on a ultra high performance tire with their Cobra. There are some good handling 15" tires but they have some significant compromises (such as no tread or not DOT legal).
A recent post stated the the closest metric size to the OEM SC size tires are 295/50/15 and 245/60/15. With that in mind you need 26.5" tall in the front and 26.7" in the rear (specs for Avid S/T in those sizes). I had always thought a 275/60/15 in the rear looked right, 27.9".
To get those heights in 17", will be tough. Generally you would have to go to a 18" or more. Most Max performance 17" tires will be about a half to an inch shorter than even the 295/50 size and up to two inches less than the 275/60. That is a bunch visually.
Take a look at this picture of my car as I bought it:
http://www.clubcobra.com/photopost/s...t=1&thecat=500
The tire where 225/60 and 275/50. Which are 25.6 and 25.9" tall respectively. Or about the height of the typical 17" tire. Since I have changed to 245/60 and 275/60 the way the tire fills the wheel well, visually, I beleive has been greatly improved (not to mention ground clearence, etc).
Then there is the whole side wall issue. They just seem to look 'right' with lots of side wall. Combine a typically short tire with a 2" larger in diameter rim and you end up with as much as four total inches less of side wall. Big difference in appearence.
With all that said, I am still kicking around a set of 17" rims
Rick