I would recommend Turbo (if you must first), Fuel pump, AFC, then 550cc injectors. I have tuned some 2Gs and it seems that they will run on the rich side and hit fuel cut before thwy had to. With the AFC you can lean it out alittle and push off fuel cut some.
Also not sure if this is aganist the rules so delete it if need be, but the is a GB on RC 550cc injectors at
www.importevolution.com. REALLY cheap.