For the air intake the best two brands out there are AEM & K&N. For a matrix I would definitely go for the AEM, even though it really comes down to how much money you are willing to spend on it lol... The AEM'S run around the 2 & 3 hundreds... The AEM is basically guaranteed for the whole life of your vehicle, it comes with a complete mounting kit so you can make sure that it is installed properly, and the best part since it would end up being located outside the engine it will definitely increase the power!!

Most of my friends prefer going AEM then anything else... and for the whoel cat back I would wait until doing the headers. For the headers DC SPORTS is a very good brand... the headers are ceramic coated which helps em stay cooler and also better performance... try to stick for the 4-1.

ahh thats all I got lol