I all you want is a 12sec timeslip ... throw a lot of boost on your stock set-up and ...yes that's all you need!!!
I would suggest a more comprehensive approach.
1. suspension
2. exhaust -- as free flowing and tuned as you like it
3. power adder support;
most will be purchased witht the power adder of choice ie. fuel, induction and computer tuned chip
Note: you can have 12 sec GT without forged internals and a 'trick' transmission, however, it woud be wise to look into how to make your engine live a long, healthy life.