greetings,
depends on your budget, i would say panel filter (piper cross or vwr), remove the pre cat (about a hours labour) and get it remapped(revo, Rtech, apr) and run the car on on either shell power or tesco momentum. Thats in my opinion the best value for money mods. The car should handle the power fine, just get the Diverter valve and cam follower checked and if your car is manual depending on milage, you might want to budget for a clutch.