http://store.quantummotorsports.com/
The WRX stuff bolted straight on but I had to reduce the piping to 2.5 as the hose wouldn't feed through due to different frame work on the bus.
They make them for the STI so you would be sweet. Great to deal with but I just went to Go Gear for the ducting
forgot to say that these were first used at Collie and I think were the reason the rotors lived