Well you stated you wanted to get max amount of hp so, you should swap in a 6spd and depending on your budget swap in a different engine. Whichever engine you have you then should re-build it and slap on a turbo. I'v been told that putting a turbo together piece by piece instead of buying a full kit can save money. Buy pipes from one place, turbo from another, intercooler from another etc. If you are in a rush to get turbo, slap it on before re-build with minimal boost then after build pump that **** up.