Let the hive mind of Engadget get that for you.
"I am looking for a device that will stream sound from one source to several recipients. For example, I want to stream sound from my TV or stereo to my phone or MP3 player that has radio and Bluetooth capabilities. I have looked into radio transmitters and they seem like a decent choice, but I can't find one that uses external power (USB or from the plug) and I would want one with a transmit range of around 50 meters. Thanks!"
Pretty happy with the 20-30W power usage.
Bought a slimline DVDRW drive and a 2.5" HDD to keep the power usage down. I have an eSATA enclosure with a 1TB for my main storage but that's turned off most of the time.
Oh yeah, this keyboard's been doing the business for me for a few years now
http://www.amazon.co.uk/Keysonic-Wireless-Keyboard-Integrated-Frequency/dp/B000L10Y5E