Its not worth turboing the the RS engine... all its going to do is blow up and cost u a lot of money. You should invest in a WRX swap or if u have the funds... an STi swap. You can make a lot more reliable power and its not that huge of a conversion, i did one to my 1993 Impreza (gc8 body also of course).
check EBAY... i bought a rolled over 2002 WRX for 2200$ on there, and i drove it on the trailer.... That way i got EVERYthing i needed for the swap, and some extra stuff.. and i ended up selling enough stuff off the WRX to pay for it