Hey, I can 100% recommend an OFT for the tune. $650 and you can even run E85 for a VERY NOTICEABLE gain. Hundreds of cars worldwide run these and have no issues whatsoever, and...at dyno days they make the similar power to dyno tuned cars with the same mods!
In terms of exhaust I have an Invidia Q300 (and cat delete) with PSR UEL headers. No drone, just a nice growl that increases with revs to a raspy howl.
My suspension is MCA race prime BTW, also brilliant
Headers, a nice flowing cat deleted exhaust and E85 and you will be grinning like an idiot every time you drive the car!
PM me if you want more info. I've spent years developing and racing the car and am happy to discuss pros and cons of my mods and share my research.