I'm building a fileserver for my small office. We do film and multimedia design. Only 3 clients connected. The server is primarily for local access to graphic assets and video files. I'm looking for advice on hardware and software required. Particularly for the RAID. I have the following objectives:

A) merged capacity
I'd like all other systems to access the data as a single mapped network drive that has an initial capacity of 10 TB. So perhaps 5x 2TB drives (plus mirror drives for redundancy).

B) easy way to increase capacity
Thinking long term, I'd like to 'easily' add more drives to the array for a potential two or three fold increase in capacity. So theoretically it could get upto a 30 TB raid array consisting of maybe 15x 2 TB drives of capacity (plus mirror drives for redundancy).

C) maximum fault tolerance
I want at least 1 mirror drive per capacity drive (in laymen's terms). So if I start with 10 TB / 5x 2TB of capacity, I suppose I would need another another 5x 2TB drives to be mirrors. So 10 drives total. But I'd also like potential for even more redundancy; with upto 2 additional mirrors per 'capacity drive' (and to be able to add them to the array anytime with ease).

D) easy way to monitor drive health
I'd like an intuitive interface for managing the raid and monitoring drive health

The other systems accessing this network drive will be running Windows, but also the odd Ubuntu and MacOS system as well.

Are these objectives attainable? What type of RAID setup do you recommend? What hardware will be required?

Also what OS do you think this system should be running? Does it really matter? I'm no network admin - just a long time Windoze user, without much Linux experience. That said, I'm not opposed to a Linux solution if it's easy enough and more practical than a Windows OS for this server. Or maybe something such as Openfiler.

Budget should hit the sweet spot for value and performance (hence my preference to use 2TB drives). The biggest focus is storage; aside from that the system just needs to keep the drives running optimally with perhaps 2 or 3 clients accessing / writing files at any given time. The hardware quote would start with something like 10x 2TB WD Caviar Blacks; about $1900 for the storage + $x for remaining parts.

http://ncix.com/products/index.php?sku=42775&vpn=WD2001FASS&manufacture=Western%20Digital%20WD

Your advice is appreciated, thanks!