There are a few streaming fans (and a few screaming fans) around here. I am one. In fact, the only source in my system is a MacBook Pro. My advice is to start simple. A simple, well-executed, multi-use computer as source will get you...well, I'd argue that if it is, indeed, well-executed, it will get you all the way there with no need for further tweaks, "optimization" or "audiophile" servers or player software. Others will disagree. Vincent is probably the leading authority around here, but if you have specific questions, many of us would be happy to give them a shot.
Tim