The 04 and 05 are the same. Yes, the UTEC is now out for it and works on both. The AccessPort will be coming out shortly, if it's not already out.
STI's have 440 injectors. You can run a VF34 on an STi at the most on the stock fuel system. Then most people upgrade to PE720's or PE800 or something like that that is ridiculously big. STI injectors are also side feed injectors where as WRX are top feeds I think. Which is why you can't take the STI 550cc injectors and put them on the STI.
Clear as mud??