Sport 530's seem to be the sweet spot. 500's would have the least lag other than stock but Im assuming you will be stepping up to a ball bearing turbo. Especially with those MSP's and downpipes, lag will not be an issue. Took me a while, but I have decided on the 530's w/ msp manis and SZ 3" expansion downpipes. I also have no plans or any desire to track the car in the future. Good luck with your search.