You definitely want both fuel and ignition control when turbo charged, I promise. How you get these things, up to you. There are a lot of ways to skin the cat. Which ever knife you choose for skinning, I highly recommend getting it installed and setup on the known good configuration that you already have, and learn to tune without boost, first. NA engines are MUCH more tolerant of your learning experience than turbo engines. Trust me as the guy that wrote the system that has run 40 engines/cars around the world over the last 7 years. I know this stuff
If you have the setup dialed in NA, as is, then you can take steps:
0) Fully tune your existing setup with your system of choice, this will take weeks or months to perfect, if ever. Get this right before proceeding.
1) Fuel system upgrade with SAME injectors - tune should not change, if it does, you no longer have sane/the same fuel pressure, fix this before proceeding (with better FPR, or pump derating etc).
2) Injector upgrade, changing just injector parameters should suffice, tune may need minor tweaks, but nothing major. Driveability and cold start may suffer, fix these as much as possible before proceeding.
3) Add boost. Use your NA timing curve, but add in additional retard above 100kPa. Use your stock VE curve, but add in a lot of additional fuel above 100kPa and expect other differences below 100kPa, too. Get a friend to help you tuning going slightly higher each pull validating it's in a good place, if not, tweak and repeat, once good, go a little further. Do not spend any time leaner than 12:1 AFR in boost. Do not attempt to tweak timing until A) your fueling is perfect B) you have appropriate listening equipment.
4) Profit.