I know you mentioned wireless control, but about wireless streaming from phone/tablet? Does he have that need?
One nice thing about Sonos system or the Audioengine D2 are they both create their own network. Pretty much plug and play. I don't have any experience with the Sonos, but with the D2 has been serving 24/96 files and I've yet to have a drop in the couple weeks it's been running. Pretty sure I've ever gone that long with the Squeezebox or Airport Express.