Does it matter what system of Magick you practice? The energy used is the same, right?

Energy is created through thought, movement, and intent. The energy is the same on a molecular level, energy is what it is. If by system you mean path, choose the one that is best suited for you. Some people prefer the strict Gardeniarian tradition, while others prefer a less structured path. I think every serious practitioner could benefit from at least some structured training or at the very least have a mentor.