If you are looking for a grille to protect the radiator for future, the best brand is Zunsport. They make one for the First Gen..
https://www.zunsport.com/en/subaru-fr/subaru-brz-–-unterer-grill?filter=295
For the facelift, its worth asking them if they can bespoke or if the first one fits.
On another note, normally how frequently do you need to top up intercooler coolant? Assume its not a sealed unit.