ok guys i need help im saving up for the roush turbo, what do i need to do to my car before the turbo comes, and i was looking at my engine and it looks like i have two cats. right now i have a MagnaFlow exhaust, lowerd, new hood, cold air intake and i know that the intake will be gone. what can i do to free up some air i was thinking of buying headers but that would be a waste of money when im going to turbo. what should i buy before my turbo and what should i buy after my turbo?

Manual check ball or electronic boost controller, boost gauge (unless kit has one?), clutch, Quaife, 2.5" or 3" flex pipe and exhaust would be nice, and J&S Safeguard.