Most Lexus Vehicles, including the IS-F are classified as ULEVII. To my knowledge all vehicles with this emission rating are 50 state legal. Therefore, IMO, an ISF sold in California is the same as one sold in Texas.
mooby, Having sold IS-F's around the country including California, I can confidently tell you that you will not run into any differences in the emissions of the car. The only variance would be the level of equipment on the car. For instance, an IS-F in California may not have headlamp washers and park assist sensors where as an IS-F in the East would most likely have them. Good luck!