Generally speaking, people who record / stream as a profession or "high-end hobbyist" tends to do it with two PCs. One high end PC for playing games and a 2nd PC to do the video recording and uploading. However, it is possible to do it with just a single desktop or laptop, but you will be taking a performance hit since it must play the game and record it at the same time. A guess-timate will be around a 15% - 20% performance hit. A quad core i7 CPU like the i7-4710HQ is highly recommended; Core i7 "U" and "M" model CPUs are less expensive, but they are only dual core CPUs.
There is such a thing a Youtube live stream, but it is overshadowed by Twitch.