how do I connect itunes from computer to stereo system

I am considering buying a desktop Apple and want to be able to play music from itunes wirelessly through my home stereo system. It's a high-end system but older with a Plinius integrated amp 10 years old. Can I do this? What components do I need? Do I need a DAC? The computer is in a separate room from the stereo so a cable won't work. Do I need additional software? I also would like to be able to contriol it via an iPad or even my iPhone if possible. Any help would be appreciated.