Just be aware I and many others have given up on using the Touchs USB functionality. Fine for a few albums on a stick, but so many exceptions on full-on drive use, that it's pretty unusable. All four of my USB drives didn't work, album art can can problems, large libraries can cause problems, etc. In fact while there are lots of defenders (usually on what's reasonable to technically expect - funny, how Logitecs marketing department never got the memo), I've yet to see a single person, with a large FLAC or ALAC library, use the USB functionally primarily. That may be a big sign. Still in many ways a great device and if you're only planning on throwing a few albums on a stick you may be fine.
Yeah, the iOS AirPlay allows the iPad to serve as remote and pitcher. Just need one of the AirPlay devices to receive.