I'm using an Iomega Home Media NAS (<$200) to serve DLNA and iTunes library to my Roku Radio, macbook, xbox 360, and iPhone. The Iomega Home Media NAS supports DLNA (and UPNP AV) and iTunes out of the box.
Luckily my house is wired for gigabit LAN so the only device on wireless are laptops, iPhones, and the Roku Radio. Aside from the re-buffering issues I'm having with the Roku, the NAS is a solid solution thats super cheap. My macbook connects to the NAS reliably and I can watch videos on my living room tv via the xbox 360.
If you want to read more about my home setup, please visit my blog post http://tshootr.tumblr.com/post/217325350/built-cheap-whole-home-media-system
If you have other questions, hit me up on PM or twitter@timmartino