It's alot more to understand than just answering the few questions you just asked. You have to understand wholly the underlying principles, and WHY. Yes, there are other components necessary to the system, they are listed in the first few pages of my thread, as well as a synopsis of what true hp aero really means. I am just finishing putting together my first system, but I believe I understand the concepts well- I just need to put them into practice. There are others subbed to my thread who have been doing this well for a long time. You're more than welcome to read and post there if you like.
No, you cannot use pvc to achieve true hp root structure. As you delve deeper into the concepts of HPA, you'll realize it's all about precise control, and pvc won't allow it because it tends to stretch under pressure, and won't give you a crisp instant on/off with the mist. We use John guest lines and fittings. They are really easy to work with, and quite small. You just cut the 1/4 hose, and push the fittings on- it's way cooler than pvc... Cloud tops and bio-controls are 2 of the nozzle suppliers popular in the thread- but don't get ahead of yourself, the nozzles alone won't do anything for you without the underlying knowledge in how to wield them. For instance- other than mist size, you'll also have to couple them with the right chamber shape/size, and choose the spray volume, mist pattern and throw most acceptable for your situation, not to mention have a timer capable of sub 1 second mist times.
That's a taste of what HPA is, it's not for everyone, but if mastered, it apparently yields very good results, is very low maintenance, saves electricity and nutes, and is really cool if your technologically inclined. See you soon if I didn't scare you away