Find a performance shop that is experienced with these cars and take it to them so you can at least get a comprehensive diagnostic of what you have.
To be able to register the car there most likely you're going to have to pull the standalone, reinstall a stock ECU, and tune the car on that with either Uprev or ecutek.
Which is better is a matter of opinion and there are fanboys on both sides but I would recommend Uprev as they have authorized tuners that you can go to that can help you in person...
Dealers & Pro Tuners