I have a 95 wrx, standard apart from light weight flywheel, apexi induction and stainless pipe. It goes well but ive had it a while and was thinking of more power. Would i see much improvement in fitting a different turbo maybe a sti one (which ones fit my model?). Or would i be better of fitting a de-cat down pipe? Or would new headers give more power than the pipe? Not looking for mega power, just a stronger performance late 200's tops! many thanks!

 

decat downpipe will free up the breathing somewhat and give good gains, if you also get a scoobyecu (ebay) or esl do similar they can get you around about 280bhp with everything else as is (will get smoother running and probably better economy)
Swapping a turbo on its own will not do anything as your ecu will have the wrong characteristics for it.