If your just after a PFC...than a Z32 is NOT necessary, rather its the other way around.
If you switch to a Z32 than a PFC or other aftermarket ECU is necessary.
Having said that, its a bit of a waste to get a PFC so early in your build up, as you will have to retune it with every subsequent mod to get the best out of the car.
Get a full exhuast, fmic, boost controller, splitfire coils and THEN a PFC to tune it with those mods.