Just placed some 215/50/17's Yokohama YK520 on my wife's 05 GT Conv... excellent tire. Superior to the stock badyears. They are also the only performance tire I know of that comes with a 60k warranty.
Since you are in TX, you should have no problem finding them at your local Discount Tire. I purchased them for 115.00 each (minus the addtional charges).
went with 215's cause they handle houston pot holes better
