In my opinion, the best company out there for cams is crower. But i have heard only good things about AEM's products. My bf just purchased their cam gears for his new engine.
To the question of "do you need to buy cam shafts", you don't NEED to... but if you want the hp gain, its a must. Esp if you have vtec. As 4thGenLude said, a Vafc goes hand in hand when tinkering with your vtec timing. DOOOO take it in for dyno. The person operating the dyno will be able to tune your car so you get the most out of your new products. A one hour session with tuning should run you under $200!!