Well, I bought a Denon Network Player about 18 months ago, and this should have been a perfect solution
I say "should" as it's not been without problems. Firstly, let me say that the actual hi-fi is great - small, attractive, easy to use, good remote control, and most importantly, a great sound. The problems have come using it to stream, and this all comes down to a Vista problem (you may have seen posts about this before, either here or on another forum!). The plan was to use iTunes to stream, keeping all our music on a 3TB server (courtesy of Raistlin). But I could never get it to play from my laptop without the music stopping every 60 seconds. When we'd tried every solution under the sun, including returning the unit to Denon, who passed it as fine, we tried using it with Gill's laptop (so that obviously means we'd tried every solution bar one - doh!) and it worked perfectly. Turned out to be a Vista Lag Spike issue, which means that with my laptop/network card, it's looking for a better network once a minute, even if you don't want it to, which messes up data flow.
When I eventually have to get a new laptop, then it will work for me! In the meantime, Gill can use it via iTunes, and we've bought a 64gb iPod Touch, which for now will hold all our music, and it works fine from this for me. There's also a Denon Remote App for Android, which worked initially but recently has starting playing up, but using Gill's laptop and the iPod means this isn't an issue!