welcome to the fold m8, plenty of members from the lanarkshire area to let you know about garages, give badbaz a P.M im sure he works/runs a garage and he knows his scoobs inside out
if the cars not been mapped then you will prob be about 240bhp ??? for over 280 you need a bigger turbo and injectors over the standard wrx stuff, a remap should see you about 270-280 bhp with the mods you have just now