I dont have built up internals but im sure i can answer a few of your questions...

First off @ 18-20psi you should easily break into the 12sec zone.
However!! a word of caution.. even though you have beefed up internals your fuel system is still the same as the one you were supplied with. Those 500cc injectors may do the job along with the SAFC.. You just have to look back at one thing.. Your Mechanical FMU!!! FMU's are good for about 9psi (reliably)..
besides anything over 9psi.. you are running crazy amounts of fuel pressure in your fuel rail !! (injectors wont be too happy).

Im not saying that an adjustable FMU, a SAFC, and large injectors wont work.. but thats a pretty rugged way to do it..
I would seriously consider looking into a stand alone system, if you are looking for that kind of performance! + it will make your car last longer !

later !