Help with potential network audio setup

A colleague of mine has asked my advice on setting up his music at home.

Basically he wants to connect a computer running iTunes to his hi-fi in the living room, so he can then control it using the Remote app on his and his wife's iPhones.

He has a Windows laptop, but he doesn't want a computer sitting there with the screen open all the time.

All I could think to suggest was a Mac Mini running iTunes, but headless (i.e. no monitor/keyboard/mouse), and just connect to it using VNC software on his laptop if need be. However he doesn't want to spend £500+. I suggested a second hand, older Mac Mini, but then I'm not sure if pre-Lion Mac's will run the latest iTunes. I'm also not sure you can get VNC software for Windows that will allow you to remote control a Mac.

Are there any options I'm missing? I considered a NAS with iTunes server functionality but as I understand it the music then can't be controlled by his iPhone.

I guess it doesn't HAVE to be the official Apple Remote app - any iPhone app/setup capable of doing what he wants will be considered.

Thanks

 

Sorry, should have added he tried that previously, he kept getting audio dropouts using AirPlay, even after replacing his Airport Express, so he gave up on it. We tried loads of different "fixes", none worked. Incidentally, I have exactly the same problem with AirPlay in my house (I've tried both a Pioneer unit that supports AirPlay AND an Airport Express, dropouts persist).