Injector question

[huey29]

Im looking to get around 250 or so hp out of my daily.. I have all the basics done, front mount, downpipe and hks hi power exhaust, intake, walbro fuel pump, N60 maf and stock t25 with hks actuator so im running around 12lbs of boost. I don't have a tune yet but that will be getting done within the next two weeks or when ever i have the time to take it down to the shop..

I'm looking at getting a set of 550cc injectors. So my question is are they needed or will i be fine without them. I know they are safe up to the 300-400 hp range but will they make a large power difference on my set up?