question about storage

[Jim Green <student.northwestern@gmail.com>]

Hello!
I have a laptop with 120G harddrive, 2x320G external harddrive,  I
don't have a desktop.

Now I am doing something serious storing some huge historical data to
mysql database and want to have some better storage solution(I hate
the two external harddrives I bought 4 years ago, need to power them
on individually and connect with laptop each time I need to use data
in them).

I have two options
1, buy a desktop with 4x2T harddrives and use lvm on raid1, I need the
redundancy of data.

2, buy some independent storage like NAS, buy another desktop with
small harddrive to access the NAS, debian installed on NAS and desktop
of course.

what do you think would be a better solution for me? I like the NAS
idea that storage is independent so I can keep the NAS even if I
upgrade my desktops, but the con is I need to buy separate NAS..

Thank you!
Jim.