We have tuning products for the G35/350Z which the FX35 is based off of. Check out Dealer/Tuner list to find out if we have a Pro Tuner near you. They can provide tuning and accessories for your cars, including tuning the factory ECU for more power, reliability, economy.
Also Jim Wolf makes twin turbo kits for the FX35.
We're currently working on supporting the FX45 which is an entirely different beast. We have a big single turbo FX45 in our shop right now that we're working on tuning software for.
The sky is the limit on the FX platform. Dream it and people will make it happen.