it is easy to hook up a toslink cable from a mac or an airport express device to an external dac. it is also very easy to build a whole house distributed music system or a dedicated audio setup using a mac computer. you first have to determine what you want: single room setup or whole house distributed system, how much money do you want to spend, and what kind of sound quality do you want to have.
personally, i wouldn't use a macbook or any mac laptop as a music server. IMO, they are not built to be left on 24x7x365 days a year like a powermac or a newer mac pro. i have been looking on the internet for a used g5 powermac that can be used as my music server. i use a macbook to remotely control my mini from another room/floor to play itunes to other locations using either cat 5e cable or wireless.
if you use an apple tv device or a mac mini in each room where you want music, you can use front row with its remote to control itunes.
as for disk, a NAS device with RAID options is the way to go but costs more $$$$,
personally, i wouldn't use a macbook or any mac laptop as a music server. IMO, they are not built to be left on 24x7x365 days a year like a powermac or a newer mac pro. i have been looking on the internet for a used g5 powermac that can be used as my music server. i use a macbook to remotely control my mini from another room/floor to play itunes to other locations using either cat 5e cable or wireless.
if you use an apple tv device or a mac mini in each room where you want music, you can use front row with its remote to control itunes.
as for disk, a NAS device with RAID options is the way to go but costs more $$$$,