The question was to invest in another NAS or to try to find a different solution. A new NAS seemed to be the obvious choice, but there were some major concerns on my part. As I mentioned, the Buffalo NAS worked great...that was until Apple updated to Lion and added an extra level of security. This added layer caused communication issues between the NAS and my Macs. I went to Buffalos website and they seemed to be unconcerned with fixing older models (Thanks for the support guys!). This leads me to the second issue....the price. A NAS solution compared to an external hard drive simply costs more money. Just for a four drive enclosure, you can pay $350 or more. Then you have to buy the discs separately.
Of course, an external hard drive seemed like a better solution for me..cheaper and fewer worries about future compatibility. However, external hard drives do not usually have RAID (redundant array of independent disks), which means you have to keep up with backups and a more inefficient use of bytes.
In an effort to solve the issue of backups, I downloaded a free copy of Carbon Cloner. This program uses software to make a copy of one disk periodically to another disk. This allowed me to buy an external hardrive and have it automatically copy new files from the main drive each week (or as often as I decided). While this seemed like the perfect solution, it works very slow when you have terabytes of data to copy. I am going to check the settings to see if there is some solution to the time it takes, but it could be the wrong solution for my needs. (I will have to update this post when I have done more research).
As it stands today, I am trying to go without a NAS because I don't want to spend a thousand or more dollars only to have the company ignore my needs in a few years. I realize that software changes and it may not even be possible to update a NAS to get past new security measures taken in the future, so that really does become a major concern. It seems that most computers will always have some compatibility with USB, so it seems like a safer bet down the road. However, copying files from disk to disk manually seems to be a major pain, too. So I am still not sure what my final decision will be. Right now I am going to try to get by without a NAS, but it will be dependent on a software solution that doesn't need several days to backup from one drive to another drive. (if anyone knows of a better solution, please let me know)