squeezebox with shairport and 24 bit support

I'm not real sure that I understand your question. If you are using a Squeezebox as a front end and your Squeezebox is capable of playing 24/96 files, then your only limitation is going to be the amount of bandwidth that your wireless system can support.

In my system, the only part that iTunes plays is to help me maintain my music library. There is no real direct interaction between iTunes and my Squeezebox. My Squeezebox just happens to pull the music files from the directory that iTunes saves my music files to. In other words, iTunes does not need to be running in order for the Squeezebox to be able to pull files from your hard drive.

Unless I'm mistaken, Squeezebox is setup for wireless. If so, then all you need is a wireless router that is fast enough to transfer your music files.

If I'm not mistaken the Express is limited to 16 bit not to mention optical connectivity. The Airport Extreme or the Time Capsule with a built in Extreme has a more than ample bandwidth.

I'm using my Extreme with an ethernet connection to a Mac Mini. The Extreme transmits Pure Music up sampled 24/96 to the Squeezebox.

Sorry that my question was not clearly stated.
What I want to do is streaming music wirelessly to DAC from iTunes.
Airport Express and toslink connection works fine for 16 bit music.
With this setup, iTunes downsample 24 bit music to 16bit.

yes, squeezebox can access iTunes music library.
But i wan to use iTunes to control music.
With Shairport hacking for airplay, we can use squeezebox as an airplay client from iTunes.
So I wonder, with Shairport+squeezebox+itunes, whether I can stream 24 bit music to my dec wirelessly and bit-perfectly.