as MrItaly! said, 180rwkw is a full exhaust, front mount and pod filter. thats maybe $1500 worth of mods?! Find a neat stock manual series 2 for $15K and spend $1500 on those enhancements and you will have your power target achieved.
P.S the R33 GTS-t 5spd is one of, if not the, toughest import gearboxes you can get so dont worry about having dramas there, especially if 180rwkw is all your after.