I think that your question(s) concerning the FMU have already been answered. It is not the prefered method of tuning for boost.
Can it be done with an FMU? Most certainly.
Can it be done with an FMU by you? Only you can answer that but your questions alone lead me to believe that you might not have the know-how to balance both the injectors and FMU for a safe tune.
None of the above can be accomplished without one or a combination of things:
1. You need some way to determine Air Fuel Ratio if you're going to install and tune it yourself.
2. You will need the FMU spring kit mentioned above in order to vary the ratio of the FMU if you plan to use one.
3. You will need a way to tune the computer if you decide to go with larger injectors as opposed to the stockers and FMU. (Yes, even injectors below 36# in size need to be tuned. A meter calibrated for an A9L and 36# injectors SHOULD get you close but it's still a crap shoot)
4. -- or you can put it all together and take it to a qualified dyno tuner. In the long run, this will likely be your best bet and probably the cheapest route. A GOOD wideband meter wth RPM converter will cost you roughly $425 all by itself. We've not even started talking about prices of the other components you might to tune (FMU spring kits, TwEECer R/T or PMS, etc. depending on which route you take).
To sum up... if all or some of what I've typed so far is greek then you're not qualified to do the install and tune on your own and can cause serious damage to the engine.
BLOWERS ARE NOT PLUG N' PLAY (except for maybe when you install a complete kit EXACTLY how the directions tell you to, on EXACTLY the unmodified motor that it was SPECIFICALLY intended for).
Experiment at your own risk and good luck.
