For sales: TGV Deletes for top feed injectors. These should bolt right up to 02-07 WRX. 08+ WRX and 07+ STI will require slotting of the intake manifold I believe. 04-06 STI are side feed and you would need to convert to side feed injectors. $150 firm. Pics later.
I'm also not sure if just slotting the intake manifold on the 08+WRX will work to fit these since they have the plastic intake manifold.