Building a new NAS/server for HD video etc.

[pushandrun]

Hi there,

I have following machines on my home network:
relatively new build Gaming/HTPC with i5 750 running win 7 with 2x 2TB HDDs in RAID 1 config and 1x 1GB system disk

Acer netbook running Win 7

3-4 year old budget Toshiba laptop running Vista

I also own a WDTV live connected via USB2 to a 1.5TB HDD in an external enclosure

I run XBMC on the HTPC and Acer netbook

My movies (1.2 TB of data) are stored on my HTPC (software raid 1)
My TV shows and music are stored on my external enclosure 1.5TB disk

I want to build a new PC that will act as a server/NAS box. I will also use it to play HD video and music through XBMC in the bedroom. It must be small and quiet (for a bedroom)and permanently "on".
I want to remove the 2 2TB HDDs from my HTPC and install them alongside another 2x (identical) 2TB HDDs in a RAID 5 config that will offer some performance enhancement with some redundancy.
I will then transfer all of the music/TVshows from my external enclosure HDD to this set-up too.
I would like to install a blu-ray writer too for back-ups. I would like to be able to access data on this server from abroad as I frequesntly travel on business

My initial thoughts were to try to find a mini ITX board and a small-ish case but finding a Mobo with 6+ SATA connectors is not working for me and there are not many case options for the HDDs I need.

I understand that HD streaming whould be fine with wireless N in all the machines

Along with general tips on the above I am hoping for answers to some specific questions:

Will I be able to simply remove the two HDDs from the HTPC and then install them into a new raid config without losing data or should I transfer the data to my 1.5TB drive first?

Should I be looking at a slightly larger case and better-specced mobo?

Can I get away with an atom processor (nice because of low power/passively cooled/HD graphice on board)?

What size power supply am I going to need to run 4HDDs in Raid 5 plus blu-ray Writer etc?

I have built my own PCs for the past eight years so have a fair amount of experience but I am getting really confused with the capabilities of the new CPUs and what I would need in order to run a server

 

[mdd1963]

YOu will definitely need to back up data on RAID 1 drives before combing the 4 into a RAID5....

WHen it comes to choosing a PSU, better to have 150 watts to spare always than to be running a PSU at 80-90% of its rated capacity...; i'd opt for a 450-500 watt unit, as 4 drives spinning up at the same time will be a 120-150 watt draw....