I don't know where you can find Chrome, but if you can't find anyone to tune it, try finding someone to tune uberdata. You can download it from the site I gave you for free.

10 psi on the Greddy turbo will not even get you close to 270 whp even with the standalone ECU and injectors. You will see around 230 whp or more depending on other mods that will help the turbo and the engine breathe better.