Linux audio distros and setting up for good audio playback.

I have read a few comments from various members stating that they have had excellent results from a linux distro for audio playback. However, when I have asked for more info, I haven't received a satisfactory answer. Searching has not helped either.  It seems the better open source people are at programming, they worse they are at building coherent web sites, which regardless half the time insist one go to some other site to get the software or not updating their web site with current information.

Two things that I've seen said repeatedly are:

• There are distributions geared towards audio which are set-up from the start for the best results.  However, I don't know what they are and, again, searching gives me only vague and confusing results with many web sites written years ago and the information being out-of-date. 
• With certain kernel settings, audio playback is optimised.  I don't know what these are or how to change them, however.

Now I can handle using the command line, as I have run servers for a while.  However, what I want are some clear instructions how to set up a linux distro, either a specific dedicated one or a regular one (Debian is my preferred choice if not using a special distro).

So my questions are:

1. I have a couple of fairly boring PCs. I was thinking of getting something like an Intel Atom motherboard and sticking it in the smaller one and using it for playback so the power consumption would be low. Would I be better off with any particular hardware, or, as long as it is fairly generic, will it suffice? My Windows PC has a motherboard which is a few years old with, I think, Realtek hardware on it. I was thinking of investigating soundcards with BNC digital output for best results, for example.
2. Should I use an audio-oriented distro or will Debian do, with changed settings? If the former, which one?
3. What set-ups are people using, and what are the specifics of the set-up (both hardware and software) and why? Would you recommend I copy what you've done?
4. Am I going to find managing my music, considering I'd be switching from iTunes, which I'm used to, easy or difficult?  Most of my music is stored as ALAC. I have no issues with converting it all to FLAC just for the music server.

Thanks in advance for any info.

This is the same link I found before. A bit of reading and you'll find the problems I mentioned already: The ideal option, DeMuDI was last updated in 2005 and has been discontinued. The web page itself was only updated in 2007. No mention of optomised kernels in the others.

What I really wish would be that someone answer who has gone through this and found a useful answer for me.

Edit: I'm just going to try Ubunto Studio I think, as previous experience suggests that it will be the least hassle.