Bro, i'd suggest to first analyse your driving style before asking for recommendations. Like what the sifus have said, handling should be the direction for your first upgrades. However, i'd really suggest you learn how to max out the stock car before adding parts whether it helps power/handling.
For me what I suggest though, get an exhaust system for your car. You'll feel more of a gain than an air filter. Powerzone's header is great for a wide powerband, though the coating burns off after time last I recall. :hmmmm: Cusco reps are also good from what I last remember. Piping size, 2" should be great, and s-flow mufflers.... stay far far away from those restrictive things.
Other than that, if you're REALLY keen on tougeing, just keep your car maintained well and start messing around with your handling. Learn how different tire pressures as well as camber + toe setups affect your car, how to have a proper driving position, racing lines, and then slowly max out the car on the stock tires before you upgrade.
For handling I'd suggest to start with good tires and maybe a strut bar if you want... Bridgestone Potenza RE003's are my favorite at the moment due to it's cost and grip. Get that + a good alignment you'll be good. Once you're better, get coilovers to fully utilize the tires. From here onwards its really fine tuning, you can't 'stage' stuff like this because everyone drives differently.
My own personal advice is that by keeping yourself slightly underpowered forces you to drive better with what you have. Adding more parts that you don't understand how they benefit to a car doesn't make you a better driver. Happy tougeing!