Creating an External Raid 1 Drive

[Yoni]

So my company is getting a video surveillance system for the office.
Basically its just a nice computer with a bunch of video capture
cards. It has an Internal 2TB SATA Hard Drive and I would like to
purchase an External 2TB SATA Hard Drive and Have it set to Raid 1 as
a backup. I want it external so I can hide it in the ceiling (with
ventilation of course) in case someone breaks in and takes the
computer we will have a backup. Is this possible? I was thinking of
getting an esata adapter and an external esata hard drive (or hard
drive enclosure) would it be possible to create a raid 1 with this
setup. Any info and links would be very helpful.

Thanks so much
Yoni Hirsch