Doing a 650 size injector is a waste, the car stock has 565s. I would do at least 750.
An STI TMIC would be a nice addition to go along with the parts for sure. Having the turbo PnP will make for a faster spool as far as I know. Grimmspeed ebc for sure. If I'm not mistaken the up pipe on an 06 is not catted...could be wrong but on my 07 it wasn't.
I am looking at doing a header before my next tune and plan to stick with UEL because he EL equipped cars I have heard in person do not sound good IMO. You loose the subi rumble however, the EL will give you more power. I was just talking to my tuner this weekend and he is trying to convince me to go EL. He said the car he just tuned with them sounded more like an EVO.