with the stock wastegate on his setup, he cannot lower it to 3psi with a manual boost controller. a manual boost controller raises boost but cannot lower boost lower than it's stock setting. lets look at the laser turbo that he is going to use, i believe that its set up for 7-8psi STOCK. You cannot lower the boost level with the manual boost controller.
Though, let me admit, i'm quite hazy on auto computerized(boost input via lcd inside car), i do believe that the auto ones do allow you to rig it up (minus or plus more hardware needed to have it operatable) to raise boost and lower it as well.
To answer your question yahama(to my best knowledge), i alsmot never flame anyone( theres not enough nice folks on here as it is ). the automated boost controller goes around 2-5 hundred dollars for one and can be mounted in your stock cd player slot(s). Be it that it may, as i've said before and you do admit, DONT go cheap when you go FI
Run it properly with a nice core cooler and many other parts that you will need.
I remember i've read a post somewhere on probetalk that a guy on there ran his car with stock internals up to 12psi. Notice he had a whole bunch of money invested in his engine bay to handle that much boost i.e wheather it be heads, IM ported, IM spacers, fuel pump and yada yada.
Like i said previoulsy, experience slowly. Mici is correct as i said before as well, boost is addictive, you'll love the extrac kick in the pants when u turn up the psi so be weary of what you are getting into.