Adding a turbo, or for that matter, a supercharger isn't easy or straight forward.
It requires a lot of custom fabrication, then you have to find a way to tune the ECU. Use a fuel pressure unit (can't think of the right name at the moment), go aftermarket ECU, get a piggyback, etc.
You can't just slap forced induction on there.
I was partially kidding, but also partially serious because supercharger is something I've always wanted to do. It's a LOT of work though. But it's been done, and if you search around you'll find a bunch of information on it.
The general consensus is: It's cheaper to buy a car that already has a turbo on it, than to custom make a setup.
Which is both right and wrong. I have a friend who builds turbo subarus. He got a free obs (rusty as hell), and built a full turbo setup for it from spare parts in his garage. I think he has $150 into it.