I'll throw another wrench into the works: Using iTunes as your software to deliver the music is going to limit the sampling rate to the conventional 16/44 no matter which hardware you deliver it with. Also, if you output via any USB 1.0 / 1.1 device it will limit throughput to 16/44. If you do utilize USB at all to interface with a DAC you want to use the better implementation of that interface, which means Asynchronous or some variation on that theme. Suggestions there: Empirical, Wavelength, Wyred4Sound, Ayre, Zodiac...there are more. Cheap implementation of USB can really make an otherwise good DAC sound very poor in comparison to feeding the same DAC through SPDIF.
Wireless is an excellent way to go. Your friend is right though, for the ultimate you'd want to go with a wired Ethernet connection to get the most from a network based server that feeds a DAC (like a Touch or Transporter). I don't think that particular difference is huge though and wireless is awfully convenient. You can easily experiment and see if the difference is audible and significant to you. The Apple Express and Apple TV are not optimal for getting the best sound - I would steer clear of them. Lots of jitter there. Go with a modestly priced Squeezebox Touch for a much better alternative in the same (just a bit more) price bracket.
My suggestion is to rip and store your files as FLAC using MAXX software if you are on a Mac, using the "CD Paranoia" setting for error correction (plenty of other options for various ripping software on PC, EAC and MediaMonkey are good ones). Use Squeezeserver to organize your library. Feed the files to a Squeezebox Touch. Digital SPDIF out from the touch to an (optional) de-jitter device like a Monarchy DIP or Genesis Digital Lens, then digital-out to a good DAC. You can control this setup remotely from your laptop using Squeezeserver, from a Sqeezebox controller or remote, or from an iPhone or iTouch using the iPeng app. Do this right and it will rival most high-end players, but with tremendous convenience and your entire music library at your fingertips.
A simpler version would be to get one of the better USB DACs that have that interface down pat as a non-issue. Fewer boxes, but you'd be hard-wired to your computer. You could also use an Empirical Pacecar to improve a USB>DAC connection if the DAC in question were not up to snuff in the USB department.
Much of this, which path is the best one, is splitting hairs and really needs to take into account how resolving your system is, how resolving your own ears are, your expectations and thresholds, budget, and finally personal preferences. Some factors do make a significant difference though so it is good to research. You can find plenty online, here and elsewhere (Computer Asylum, Computer Audiophile, Empirical Audio, Wavelength Audio, etc.).
Hope there's some help in there for you.
Wireless is an excellent way to go. Your friend is right though, for the ultimate you'd want to go with a wired Ethernet connection to get the most from a network based server that feeds a DAC (like a Touch or Transporter). I don't think that particular difference is huge though and wireless is awfully convenient. You can easily experiment and see if the difference is audible and significant to you. The Apple Express and Apple TV are not optimal for getting the best sound - I would steer clear of them. Lots of jitter there. Go with a modestly priced Squeezebox Touch for a much better alternative in the same (just a bit more) price bracket.
My suggestion is to rip and store your files as FLAC using MAXX software if you are on a Mac, using the "CD Paranoia" setting for error correction (plenty of other options for various ripping software on PC, EAC and MediaMonkey are good ones). Use Squeezeserver to organize your library. Feed the files to a Squeezebox Touch. Digital SPDIF out from the touch to an (optional) de-jitter device like a Monarchy DIP or Genesis Digital Lens, then digital-out to a good DAC. You can control this setup remotely from your laptop using Squeezeserver, from a Sqeezebox controller or remote, or from an iPhone or iTouch using the iPeng app. Do this right and it will rival most high-end players, but with tremendous convenience and your entire music library at your fingertips.
A simpler version would be to get one of the better USB DACs that have that interface down pat as a non-issue. Fewer boxes, but you'd be hard-wired to your computer. You could also use an Empirical Pacecar to improve a USB>DAC connection if the DAC in question were not up to snuff in the USB department.
Much of this, which path is the best one, is splitting hairs and really needs to take into account how resolving your system is, how resolving your own ears are, your expectations and thresholds, budget, and finally personal preferences. Some factors do make a significant difference though so it is good to research. You can find plenty online, here and elsewhere (Computer Asylum, Computer Audiophile, Empirical Audio, Wavelength Audio, etc.).
Hope there's some help in there for you.