Got one on my Hawkeye WRX, fit no problem, got it from Revolution/Just Subaru down in Newcastle
Link to Hawkeye Exhaust section
Looks great, its pretty loud, although it comes with a bung to silence it a bit (mines is missing the bung)
Not sure how it would fit on the Prodrive set up, but fit perfectly to the stock WRX down pipe
Shouldnt need a map as you are just losing the 2nd cat that isnt monitored
Heres a photo of the old and new for comparason
Cheers
John