NAS / Backup Design Questions

Not sure if this is the right forum or if I should post int he Networking one, but here it goes...

I'm trying to come up with a strategy for backup of general files and media. Here are a few notes and requirements:

• Need ability to take backup of everything (preferrably on single hard drive) to safe deposit box. I will use online backup for only most critical of documents due to bandwidth limitations.
• I have about 800 GB of videos and pictures and another 50+ GB of documents, program data, etc. This is expanding at 100+ GB per year (almost all pictures).
• I currently have a 1 TB main drive in my system plus 2 1.5 TB drives that I manually backup to, then open the case and swap out every 3 months or so. One of theim is starting to tick, so it may be failing.
• I use Acronis backup to image primarily the system drive. I believe it is limited to only system drives (non-networked) for the protected zone feature (which I use).
• My wife, myself, and the TV would currently share a NAS, though my 2 kids are approaching the age they would benefit as well.

My thought is that I could put the 2 1.5 TB drives into a NAS and use it to store all of the media files, plus have a "backup" area for the 50 GB of other documents in standard format. Then, I would buy/find another drive to keep in the computer at all times for the Acronis Zone and possibly to back up the media files. If I went with a RAID configuratin on the NAS, then I would need a 3rd drive there as well to be able to put one in the Safe Deposit box now and then. So now a few questions:

• Does this seem like a good approach? It seems inefficient to me, but I'm not seeing better options.
• I tried a D-Link DNS-323 (I think...it was 2 bay) around Xmas and it was so slow that video streaming via an ethernet cable on my Gigabit router failed or was very choppy. I've found various performance data, but it differs broadly and is inconsistent in use of Mbps and MB/s (8x less than Mbps in my mind).
• I would like a NAS that is scalable. Most say the max size is 2 TB, but won't they expand later with firmware updates?
• I don't want to spend a ton on a NAS...around $200.

I'm leaning toward a Synology DS211j at the moment, but I really don't know much about the NAS manufacturers, so any help would be appreciated. It would really help to know if prices/technology is fairly flat or would waiting 6 months really help?

 

If you have an old PC around I'd suggest ServerElements NASlite, worked for my NAS and had no issues streaming video. An option few seem to use,if you someday have a larger budget, is Window Home Server. It has automatic backup of networked PCs, good video streaming, and other options, I only use it for storage of my video, pictures and an area to transfer files between systems - a single share point, instead of everybody sharing folders. You can add drives, they usually have empty bays & they have an eSata (make sure you get it with a port replication eSata) and you can add more drives. My Hp model has eSata without the port replication, so I can only add 1 external drive. You can add and remove drives from this system rather easily.

For under $200, but an old pc & use NasLite.