If you drop in a set of STi pink injectors from a newage STi and go for something like a VF35 (STi Turbo) or TD05-16g Front entry then your desired 300BHP will be achievable with ease. You should see between 300-330BHP
If you then go for a bigger intercooler then a TD05-18G or 20g will see you running 350+.
The WRX should have a high flow fuel pump fitted to be on the safe side.
But going on what you said this morning wanting just 300BHP then a 2nd hand VF35, High flow fuel pump and a fuel pressure regulator should see you there.
As we found out this morning you will have to either go to an ecutek dealer or source an un-locked ECU from
http://www.gradea-subaru.co.uk/ due to you rather unusual 2001/2002 PPP not having the usual GEMS board inside, but has been reflashed, presumably with an ECUTEK Lock-down.
This is what your ECU should of looked like, and as per others I have seen in the past :
http://www.arcanumdesign.free-online.co.uk/PPP2.html
The other option would be to get a TD04 Hybrid from andy forest and this should see 290-300BHP
You current turbo is a TD04 so could be used as an exchange unit with andy forest
http://www.andyforrestperformance.co.uk/index2.html
He may also be able to remove the ECUTEK lock on your ECU if you as him nicely
