I don't know. What is a SAFCII? And how much $$ and hp are we talking about?

 

SAFC= Super air flow converter, it is a piggy back for your ECU so you can self tune the AFR you can lean it out or richen it up, it also has some good featers and monitering. you can watch you throttle postition digital RPMs Knock and a few others. it is mainly for turbo car and tuneing but on a GT or GTS with headers the car needs a slight tune and it will gain around 10 more at the wheels sometimes even more.
I have seen a few GTS eclipses with headers\exhaust\intake and a tune dyno right around 200WHP and a couple over that, which is good for those cars when a stock dyno will only get around 165ishWHP

as far as price you can pick a used one up for around $150 and new around $300

 

Is there a website i could look at?

 

a website for what?