Personally, I use Serviio[/url] on my iMac (it’s multiplatform and free), and this serves up everything, vids/pics/music, to my Samsung TV downstairs. The Samsung can play most files natively, DTS audio being an issue, so I have transcoding turned off in Serviio, so none of the quality drop that Cougar has. I have my computer on most the day, so depending on whether you do or not, this may be an issue.
All this is done over WiFi using Virgin Superhub.
So in summary, get your server and, I assume it’s DLNA that is the streaming protocol, install a DLNA client on it, and that should be half the battle.