First I will list the parts I used:

• Zirco mAX Micro-ATX Desktop Case with 300W PSU
• VIA iDOT PC2500E  PC-1 Mainboard
•  Kingston 512MB 533MHz DDR2
• Seagate Barracuda 7200.10 x 2
• 2 x SATA cables

Total cost came to £221.19 inc vat.   Most parts from Linitx.  If mixing/matching suppliers, I could have got the disk prices down to make the total just over £200.

Okay, as mentioned, I installed Debian, but to do software raid on Debian requires a bit of a configuration guide - I adapted this one to my circumstances - http://www.planamente.ch/emidio/pages/linux_howto_root_lvm_raid_etch.php

I chose Debian as it’s the Linux I use most.    Samba configuration I am not going to cover here, its rather simple to sort out - just adding the relevant lines of configuration to add the relevant shares - and adding encrypted samba passwords for users to access the shares.   I then configured the iptables firewall to restrict access on all bar ssh to the local subnet only (I run a non-nat configuration with a /28 of IP’s routed to my house).

I also installed a basic X-windows configruation, Firefox + an email client, and my NAS is now my instant-on, low-power web station in the office - and it performs well desptite only having 512Mb of ram.

Overall performance of the box is excellent - only thing its lacking is a 1Gig NIC - however my network isn’t 1Gb currently - so this is academic.  Its quiet (unnoticable that its on in fact), very cool (in-case temps not registering above 34 celcius now) - despite the lack of case fans.      It also can average 99.9% of my 100Mbit network constantly when uploading a file or downloading also.

Downsides are I have already used 50Gb of the 200Gb of raid-1 space I have - just backing up essential documents and my photo album.    Once I sort out my mp3 collections tags, that’ll be another 30Gb used..    My aim is (if possible) to load 5 disks in time to the box, an addition 2x 1Tb disks in raid-1 for additional data, and a 5th one (which will probably need to be external) of 1Tb of scratch, non-raid storage.