Are these components fit for a Media/Web/File-Server

Hi, I'm new here and I need your expertise on hardware for a server that I want to put in my living room  
There are already quite a few threads here about that topic but I would like to ask you for some feedback on the hardware that I found.

What I want to do with the system:
- Run a DLNA server to stream to my TV
- Run NFS and Samba to share files with my Linux and Windows PCs
- Run a webserver and FTP server that will be accessed by a few people (max. 5)
- Run transmission-daemon to download torrents.
- Run a MPD server and connect my stereo to the system (so I need a proper sound card I guess)
- Maybe install OwnCloud

I will probably install Ubuntu Server 12.04 LTS as an OS.
The system should be relatively quiet (it's going to be in the living room) and gentle to my electricity bill  

The components I have found so far are these:
AMD A4-3400, 2x 2.70GHz CPU
ASRock A75M-ITX, A75 Mainboard
Gelid Solutions Siberian CPU-Fan
Fractal design Node 304 Case
Corsair ValueSelect DIMM Kit 4GB RAM

Is there any PSU you can recommend? I initially thought that was part of the case but it turns out it's not.

The RAM is probably not the crucial thing but it was recommended to me.

So, what are your thoughts on this system configuration? Looking forward to it and I thank you in advance