400hp Garret genesis coupe 2.0 turbo upgrade ?

I have a 2.0t genesis coupe & would like to Purchase a 400hp bolt on Garret turbo on my coupe. How much would that cost me to get it put on & get it to 400hp? What additional upgrades do I 100% NEED & how much would it cost me. I don't know much about turbos so please explain as much as you can. Remember I'm a noob. Haha thanks!