Options for unit that can stream music to USB DAC

Hi all, I am looking for something that can stream music files from my home server to the Benchmark USB DAC1. What are some of the options available out there?

I have an HP MediaServer connected to the home network. I need something that can be connected to the wall with a network cable, can pull .wav files from the HP server and stream to the Benchmark via USB.

I would like to be able to control the unit via iPad and use iPad to browse through the collection. I am hoping to avoid having to use a laptop.

Also, what would be the software to use, both on iPad and whatever stand-along product you recommend? Or is Apple Mac Mini with Amarra my best choice that would satisfy these requirements?

Thanks in advance,

Apple TV comes to mind, but won't output via USB, you'd have to use optical.
Just a wild hair, has anyone used something like this:
I would suggest a Macbook or Mac Mini running Pure Music. Your NAS is connected to the Mac via ethernet, and can be in another part of the house if desired (mine's in the basement). Your files stay on your NAS but you create a library in iTunes. You control using the Remote app from the iTunes store.

This works like a charm and is the best solution (IMHO) other than a dedicated server.

Also, I've tried just about every Mac based playback software available (Amarra, Pure Music, Audirvana, Decibel, Bitperfect, Fidelia), and I always came back to Pure Music as the best for both sound and functionality.

Hope this helps.