Squeezebox touch, Apple TV or Apple Airport Expres

I'm interested in streaming music from my IMac to my stereo.

I have a Moon 100D Dac that I use with my Onkyo ND-S1 IPOD dock.

I would welcome suggestions. I understand that with the Apple products, I can use a optic cable into the DAC. But is the sound good?

I have read rave reviews about the Squeezebox Touch. Is it much better than the other products?

Thanks very much.