Everything looks good to me except the Flowmasters. They may sound good, but performance wise they suck. At the very least weld in a set of performance mufflers other than the flows. Or... Substitute a complete cat back system for the Flowmasters. Magnaflow, Bassani, Borla Stinger, etc. all make good systems that will provide more power than the flows. I'd also get a CAI versus just a drop in K&N. It's a well known fact that these cars are very restricted from the factory when stock. Opening up the intake and the exhaust is the best way to make power on these cars.
I'd say you're looking at possibly 440-450 RWHP with that combo and a good tune.