Hardware :: Low Power Linux Home Server

I am looking for some advice on a Linux home server. I'd like it to be low power and reliable. I have searched and found a lot of information online already, but it's too hard to choose due to the many options and opinions.

The main reasons for me to get a home server are (more or less in order of priority):I'd like to have my files centrally, so I can reach them from my laptop, my PC, my phone, from work etc ( or stream them)
I'd like to have my own e-mail server for my own domain(s), perhaps also Jabber
I'd like to have my own web server to develop and perhaps even to host a website
I might play around with home automation in the future
Of course I am not here to ask questions regarding the software I would need, but I'd like to get a nice low power (I am a bit of an environmentalist, but not extreme) and reliable server.

I also get the impression that many people like AMD Geode processors and the choice is certainly not limited to these products. I am here for suggestions.It's not a necessity that the server will be small. Actually, I think I'd like to have something with two discs, so I can use RAID (no experience, but it makes sense to do), so the B3 looses from the Via here.Also, I like a bit of flexibility, so I think I would prefer a home network in the future with a separate modem, router, server and WAP over an all in one solution. Perhaps even have the hard disks in a separate case? Actually, I think it makes sense to place a server out of sight (aesthetics, theft, etc), while a WAP should of course be fairly visible.

At the moment, I do not have lots of files to store, but I think it makes sense to get decent capacity anyway (at the very least 500 GB and expandable).Making a good choice is more difficult for me than spending the money. I'd be happy to spend something around 400 - 600 for a good product. I am able to put components together myself if that would give me a much better product for the same amount of money (did it before, but not so often).