Yeah you can make your own easy enough, and if you plan on using a 5v USB supply it's the only option afaik.

If you want to buy them there are 2 options:

Sounds heavenly in U.K. ; works with a plug-in transformer
AV connection in Denmark ; works with a 12v trigger out from a processor etc.

Relaxing room 1: Vizio P65, Oppo 203, Emotiva XMC-1, Beolab 5.3 speakers.
And a big headache getting it all to play together.

Relaxing room 2: Beocenter 2, Beolab 2.1 speakers.

Music room: Apogee recording with Nuemann, Dynaudio and Meridian speakers.
And a big headache getting it all to play together.