I need help on chooing the right way to set up a RAID 1

Hello all,

I bought two western digital 2TB green drives a while back and I am planning to make some use of them during winter break, and would like to put them in raid 1 for file backup.

I am only going to back up videos, pictures, and some other files, it will not be a system backup, no NAS.

My motherboard is Asus P7P55D-E PRO

I am currently looking at external raid enclosures, I don't feel like using an onboard raid controller, I might be switching my mobo in a year or so.

Here are the questions:
1. Should I go with software raid or external raid enclosure? why?

if software raid
2-1. Which software is the most reliable?

if external raid enclosure
2-1. Is this enclosure reliable?
http://www.amazon.com/Cavalry-eSATA-External-Enclosure-...

2-2. if I have a $100 budget, what are some of the better choices for an external raid enclosure? eSata ONLY.

if neither software raid or external raid enclosure
3. Why? What do you recommand?