Forget about just bolting on the GT 60 turbo.
In theory, you can run the stage 1 on piggy back ECU and standard fuelling.
Personally, I think you play with fire if you do this.
First of all, the piggy back ECU will never meet the requirements given by a single turbo setup.
Second, the fuelling will be maxed out very quickly as the 550cc injectors will reach their limit (together with the fuel pump) way before the turbo begins to enjoy itself. In case you run JapSec injectors, forget PHR stage 1 with these.
I run the following setup on my Supe :
PHR stage 1 turbo kit
PHR stage 1 fuelling kit (twin walbro pumps, PHR fuel rail and 720cc injectors, fuel pressure regulator)
AEM stand alone ECU with 3 bar map sensor and HKS DLI
RPS clutch with PRS lightened flywheel
Some accessories also need to be added if you go single (BOV, EGR Block Off Plates, Oild catch tank, FPR) ... don't forget these as they are necessary.
A PHR Map ECU II, which is a powerful piggy back ECU, will also works on a single ... but not as nice as a stand alone.
Forget to simply look at the 5000$ costs for the PHR stage 1 turbo ... if you want to have your Supe running safe, go at least for a PHR Map ECU II, bigger injectors and the necessary accessories as mentionned above.
Do a good research to see what you want to do.
Have fun