if it was my workshop and you came to me as a customer here's what i would be suggesting
1. fuel pump
GTR33 fuel pump (good for 300rwkw) and direct fit, if you are worried about using an on old pump then bosch 040
2. injector duty & max
the stock injectors will max around approx 250rwkw give or take. it depends on the tune, and fuel reg. we would upgrade the reg to the nismo item (direct fit) and tune based on that
3. power and boost pressure
you should be able to make 240rwk to 250rwkw ish on your car depending on tune, engine condition etc.
i would expect to run around 1.3bar on the this at the most, perhaps 1.2bar but boost shouldn't decide your power goal or how the car will be setup.
dyno it and tune it at 1 bar and see what comes out, usually after 1 bar every psi extra on a highflow usually only gives very small gains, but worth a try anyway. 1 bar is probably a good indication of power made
-summary -
add gtr 33 fuel pump (or 040 if u want new). add nismo fuel reg.
full tune at 1 bar and see what comes out, montoring knocking (on the safc), fuel pres (dyno sensor), inj duty (consult cable) and try and tune as best you can
i would go for a 2nd hand safc II the reason being cost and simplicity. a piggyback solution should be simple and cheap. if it doesnt fit under those then dont bother, i wouldnt bother with emanage or fcon as your budget probably doesnt allow for it and the safc II will give you 90% of what you need for a less cost.
i dont play the whole "the top 7 gtrs use this ecu" blah blah crap, her car its not going to be a top 10 gtr nor is she in japan so its irrelevant.
any ecu can make a car go fast, its how well its tuned and of course additional features it has, but that being said i dont think it applies in this case