Welcome to the boards!
The cheapest, quickest way to make power is a turbocharger, for sure. Otherwise you'll sink a lot of your money into the car. =) That is, over time, you will, rather than right off the bat.

So, assuming you do get a turbo kit, you would probably want Perfworks piggyback ECU, as he's talking about a sizable increase in power with one of those. HiBoost's turbo kit apparently makes the most power, at about $3.5k, and I think Perfworks was talking about the piggyback costing from $500-$1000. After the turbo kit, you'll want an exhaust, weather custom or otherwise, to take advantage of the turbo better. Some form of custom intake setup is usually included with the turbo kit, so that's generally fine. But something you may want to consider, is if you go any further with the tuning, other than an exhaust, turbo, and an ECU, my guess is that you'll be at the edge of the limits of the internals of the engine, so you may want to go forged, some hardened Titanium valve retainers, custom cams, with a flywheel and clutch to hold up to the power. We're not quite sure how far the tranny can go, yet, but it seems to eat synchros, but my guess is that that's caused by the excess slop in the engine mounts, so some urethane mounts would be suggested, lest you eat through them like candy, making that sort of power. =) Just a few things to think about for you.