keep the airbox, and get an Apexi panel filter for it. Stock turbo will hold 10-12psi nicely, with a decent boost controller everything else on the list looks pretty good to do them power figures, guessing your turbo is the stock 34 item with the OP6 rear housing if it is then just send it away to get highflowed rather then spending big $$ on a HKS item.
Fixed the brumby today, LH front driveshaft was stuff, while i was under it though i found the rattle, tail shaft uni is buggered the list never ends