Since he doesent know what an external gate is to begin with i highly doubt he will have the knowledge to do a new turbo setup himself.
R33_KRAZY
Unless you are planning on going all out with new injectors/fuel pump/afm/clutch/ecu etc etc i wouldnt bother as the turbo you are getting will be somewhere in the 500-600hp range coz its an external gate turbo. If the turbo was smaller then they wouldnt bother making it external gate