Apple and MOG

All I do on my computer is listen to MOG/Pandora/LastFM. That's it. No transferring physical CDs to the iTunes library, no photos, no movies, no apps, no anything else. What features should I look for in an Apple? Please note, I will be running "wifi", not hard-wired. Please let me know what specs (such as memory, processor and storage) I should order without wasting money on things I don't need. Thanx.
How do you plan on getting the music from your computer to your stereo(s)? Also, do you need a screen/monitor for the computer?
You don't need a computer for those functions, something like a Squeezebox touch would work.
I'm looking at the Apple as the "source" component attached to a USB DAC, then right into the integrated amp. In other words, computer will be part of the hi-fi proper. The question is...what specs do I need in the Apple GIVEN WHAT I DO, not how do I hook it up? Thanx.
Saeyedoc is absolutely correct.

The Squeezebox Touch does all of this and the sound quality is to notch for the price. For what you want to do, you don't need a computer at all. However, if you have other reasons for wanting a computer, just get the most basic and cheapest Mac available.
If you're going to use a USB D/A, then any Intel processor based iMac or laptop will work with a minimum of 2Gb RAM.
Sorry to say, Logitech just announced it is no longer making the Squeezebox Touch. Probably not a good time to buy one.