well, im interested to get 19" for my S, but im not sure how it handles and acceleration. also if it smooth or not. please you guy give me your opion.
thanks all

 

They will accelerate slower because you can't match the diameter of the stock tires, you're basically installing taller gears. And they most likely be heavier, slowing you down more. And yes, they will probably ride rougher.

16's and 17's give the best performance on the S2000.

 

it will feel like a go kart

try 225 all aroun or 225 front and 235 rear 19's

 

19 inch wheels will make aceleration
the ride and handling will be affected also...

 

I agree, there just isn't any good size tires to use and the wheels are most likely going to be heavier. If you are doing it for looks go for it. If you are worried about the performance 17" or 18" would be the max I would recommend.
If I can help let me know.