My opinion is start with the CAI or SRI, the temp issue is just someone speculating as I doubt they actually did temp readings inside the wheel well. The main benefit from either of these is they eliminate the restrictions of the factory setup. Exhaust is fully custom at this point unless $1600 for a cat back from JunBL with very minimal gains is in your budget. Down pipe is available from Tork Motorsports and the CAI or SRI from 6th Element which either is a good place to start.