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.
I've been streaming from an iMac using a Moon 100D with an Airport Express for eight months and the sound is exceptional. I've been so happy with it that I went to the Moon 300D using the same Airport Express.

I use a glass fiber optical cable from the Airport Express to the DAC, though that's probably the least critical component in the signal path.

I don't have any experience with the Squeezebox Touch, It has a lot of fans but I don't think you'd be disappointed with any of the Apple products. The Apple TV would give you other entertainment options but I haven't tried one yet and don't know how it compares sonically with the Airport Express.
If you want to stick to the Moon 100D you have three options:
1) USB from iMac
2) Toslink optical from iMac
3) Add a streamer like Airport express or Squeezebox

(1) and (2) should be similar in this case as the 100D's USB implementation is Class 1, so limited at 16/48. So depending if you want to place the DAC far away from your Mac, then you should go with optical. You should only use short-ish USB cable.

(3) gives you more flexibility on placement but ofcourse you have to buy an additional device, if you use Sqeezebox then you have to run squeeze server software on your mac and use the Touch to "pull" music from your mac. There is a dedicated control software that works on your ipod/iphone or ipad. Airport express integrates completely with iTunes and Airplay. In both cases you can take digital output from streamer to your 100D. Please note that Airport express also limited to 48k, but Squeezebox can do Higher resolution.

Another solution is to sell the 100D and buy a newer DAC with asynchronous USB Class 2 input. Where you can run USB cables up to 5m.
I'm currently using an Apple TV gen 1 as a music server, connected to the new Cambridge Audio DACMagic Plus via Audioquest Optilink3 toslink cable, which feeds into a CA 840aV2 amp. My music files are stored in AIFF format. Results/sound are amazing! Just my 2 cents worth; good luck with your research.
No Apple experience, but the SBT is an amazing product. Probably can't go wrong either way.
I have all three products but only play music with the SB Touch. The Apple devices sound bad into the same DACs compared to the Touch. My systems are pretty good but certainly not ultra resolving. If you are just listening to mp3's then the Apple streaming devices will be fine.
I'm having very satisfying results with 2012 i5 8GB Mac Mini > ethernet > Apple Time Capsule/Airport Extreme wireless > Squeeze Box Touch > SP/DIF > DAC.

The Extreme is a substantial improvement over the Express.