How would you go about increasing performance on your 2009 sti what parts are needed?

How would you go about increasing performance on your 2009 sti what parts are needed?
A stage one upgrade would be a tuner computer chip. Usually about $3-500.Stage two would involve chip, intake, and exhaust. Plan on $1000.Stage three would be stage 2 plus larger turbo = big bucks, plan on over $6000.A chip will give you better drivability and is a good way to go.