well with that setup you should be able to run 15psi safely on a stock engine and not blow anything up... just make sure you have the fuel to supply it.. 3" downpipe should be good for now... bigger downpipe you go less torque but more flow so therefore more power at the end of the day
if you spent all that money on the upgrades i would spend the extra and get an aftermarket ecu... if that can't happen get an safc and a hks type k fuel cut defender and make sure she's tuned....
fuel is really really important.. more so than really anything else...
the lexus afm is a trick just like the fcd for the ecu... it sucks in 25% of unmetered air which is why you then need 550cc injectors to counter as they are 25% larger so they match... fuel cut is raised to about 20psi i think...
if you can tune it all correctly you should be in the 12's
you'll nail that gsr hehe