I've tried to list the most basic and frequent mods that keep the car closest to stock but adding safety, comfort, performance and reliability. They are readily removed to return the car to complete stock (please note that this is my personal list):
Transmission cooler
Air plenum stiffener
Interior armrest pads/console tray
Smaller diameter supercharger pulley and tune
Clear plastic protectant - for leading-edges/areas
Integrated battery charger - if your gal sits and waits for you for long periods
Short shift kit
After this, many other options are available to take the car wherever you want to.
Finally, I'll see and raise the comments of Shadowman and others. The FGT is simply playing in a different league - of historic value, mission-focused performance, exclusivity, likely appreciation, astonishing performance, visual aura and reliability (at least when compared to any other exotic). It's like comparing a fish and a bicycle. Where do you start??