send your motor to tomei and have them build it for you ^.^.. they can build a 400hp sr easily if money isnt an issue..... to attain your goals you might want to do a rebuild, get new cams, a better turbo hks, tomie makes a new cheaper version of their awesome turbos.. and im taking price cheap, not quality... new valves, a bov by any company usually works, better turbo intake manifold, a turbo timer, boost controller greddy makes em good! but they can be pricey!! and the most important part would vbe a TUNE!!! nslapping parts on a car and not tuning them will kill and grenade your motor...if you can afford it get an aftermarket ecu by AEM or even have one chipped by MINES
and then you will easily attain your power goals... it sounds cliche but always go name brand when building a motor... or do lots of reaserch on brands you may not have heard of..... and if you cant search on zilvia use google! if you type a Q in google about anything sr related it usually directs you to older zilvia posts that you can look into. thats what i do!
to avoid flaming and if i honestly cant find ANYTHING....ill bite the bullet and ask zilvia.. usually if your honest and say youve searched EVERYWHERE youll get some good response.. just search search search! everyone on this forum has been in your shoes man..(well almost everyone thats been on here for a while) we feel for you bro..in the end when you do things by your own knowledge and hard work you feel much better about the end result.
