Are they all pretty much the same? I.e. one will fit all models?

 

3-ports are a direct fit electrically between <96 and 97/98, although obviously you need to connect/route the additional boost hoses.

Turbo - Top Port
Actuator - Middle Port
Inlet - Bottom Port

the connector on an MY99/00 is different so you would need to adapt that.

not sure about MY01> but expect it's the same as MY99/00