Remote backup solution

Hi mates,

I have a client who wants to scan all his paper documents into a computer, And since he needs to keep the data for along period of time, He wants an out-of-office backup too.
I bought him this cute NAS with 2X500GB hard drives in mirrored raid configuration as the primary location of documents at his office :
http://www.plonter.com/detail.tmpl?s...71207&lang=heb

Now....I need to find some solution to create a copy of the data on a remote hard drive.
He has 50K/s internet upload speed, So I guess it'll be best to backup data at night.
I thought of buying a WD or SEAGATE simple NAS drive, Locate it at his home, and somehow configure it to sync to the drive at the office

I would be happy for your suggestions.

Thank you !!

Something for you/your client to read;

http://blogs.techrepublic.com.com/10things/?p=285

Thanks for the valuable info CCT.
I'm thinking more like FTP server on the hardware side and something like COMODO backup which is freeware. I prefer this much better than some online backup solution.

After playing with some software solutions, It seems that a simple NAS box located in my client home (His Raid is at the office), And the new Cobian Backup V.10 who just came out Beta yesterday, Will suffice to my need and to the client's budget.
V.10 has built in FTP incremental 7zip backup (For some strange reason it doesn't support hebre unicode filenames, While V. 9.5 did.....So I decided to go with the 7zip incremental method for unicode compatibility and low bandwidth usage), And it also has a built in email notification mechanism.
The only thing that bothers me is that I need to leave a computer to handle the FTP tranfers at night, And I wondered if there's an built in FTP backup feature in some NAS box on the market......