Apple AirPort Express...
DOES WORK*
*Okay, it works, but with issues, and I shall be sending this device back. Firstly it didn't work how I wanted it to, it only transmits via iTunes. I managed to find software called Airfoil which lets you send any audio, much better! However, when using this with videos such as on YouTube, there is a 5 second lap creating lip sync. There is a fix for this, using Airfoil's own video player... but it's only available for Mac's at the moment
This is where the real trouble started though. After I decided to pack it back in it's box, I plugged my jack back into my Surface to play some music and there was nothing... no sound at all. I unplugged it and tried playing through my monitor speakers, no sound. Tried playing it through the Surface speakers, no sound! At this point I uninstalled both the AirPort Utility and Airfoil, no difference. The weirdest thing was, I managed to get the 'ding' sound when moving the volume control up and down, but nothing else. I could only get this through the Surface speakers, nothing extended to my monitor or Hi-Fi worked. I couldn't be bothered mucking around with it and just decided to restore Windows. It worked fine after. So a warning, I don't know what it done exactly, but it messes with your sound big time!