I never built a PC, but I know how to put one together. I am just getting your opinion on a PC set up that I can play games on and stream directly on. One more thing... I am also planning to get that LG 21:9 3440x1440 monitor that Linus reviewed. Also throw in opinions of mic and headphone choices. I am coming off of console so I need to explore options.
Budget?
3440x1440 panel sounds crazy
None. I am planning to go balls to the walls with this build to keep up a good quality stream, but with sensible components. Nothing like dual Titan Zs with an intel 8 core. I just been having a bit of self conflict choosing parts.
http://pcpartpicker.com/p/3AeOn
Seeing as you didn't specify a budget, I think this would be a pretty decent build. Obviously how much storage you need can be easily modified, so I just threw in two 2 TB drives since you may be uploading to youtube (you did not specify). As for graphics card, I'd recommend waiting for the rumored EVGA 780 Ti that has 6 GB of VRAM because of the monitor you're going for (I just made a vague guess of $750, we don't know how much it will cost for sure). The power supply will be enough to SLI in the future, if you wish. And the hex-core i7 will be absolutely great for streaming.
A more concrete budget would help a lot, though. It wouldn't have to be a very specific number, it could even be something like "I want this build to be cheaper" or "I want to spend more to make this build better." Although your comment on Titan-Z's did help me not go completely ridiculous.