Hi everyone first post in this forum

Well I've been researching what would be the best equipment to use for a RAID5 to edit video so I was looking into:

External enclosure with 4x HDD's but, my problem is what to choose bare in mind performance/price(not looking in spending 500$+ ahah)!?

I'm thinking in buying an Icy Dock MB561US-4SB-1 Quad Bay eSATA anyone has any experience with these?
Connected to my onboard RAID(not sure about performance!?)

Now my HDD system is: 160GB WD Raptor 10k RPMS SATA2 (system) + 1TB normal storage + NAS.

I want to add the RAID + another drive to save my rendered files.

Toughts please?