ok if you have (or plan on getting a chipped ecu) then keep you injectors stock for now. Change out to the 450's when you turbo. You could essentially run them with the chipped ecu but you'll have to take out so much fuel it'd be retarded. (think 450's are almost twice the size of stockers)
So go to
www.tunertoys.com and get yourself a set of 450's like i did. Craig runs the joint and you can look him up on homemade turbo as well. Register at homemade turbo because a lot of places give disocunts to HMT members. The injectors are good because they're warranty'd. I know some people got a bad batch before they changed the manufacturer and craig replaced all of them without a problem, plus they're cheap, and i run them
once you get the turbo on, i assume you'll be tuning with crome or uberdata. Basicall you need to find a stock map of your car, modify the map to include boost tables (to whatever pressure you will use). Then you need to scale the whole map to 450CC injectors and adjust the fuel pressure on the map if applicable (although that should be stock). Congratulations you just made a basemap. Now hook up the wideband and/or EGT and get tuning!