Best drives for software RAID0 -=and=- HW RAID5?

Hi!

I've just bought a delicious new 8 core Mac Pro for video editing, so want heaps of fast, reliable & cheap storage

I want to buy it piecemeal, so rather than spend £1,000 on 8TB of storage, a RAID HBA, & an external enclosure, I initlally want to buy 2 drives that I'll put in the Mac Pro & software RAID0.

Then, after I've done some jobs & earned some money (fingers crossed!) I'll be in a position to buy 2/3/6 more & get everything I need for a fast RAID5 with some redundancy.

All of my research pointed to WD Caviar Blacks as having the best sustained xfer performance which is key for video, so I ordered 2x2TBs on Amazon. Within 15 minutes, though, I'd discovered the TLER not being available on newer WD drives, so I quickly cancelled the order.

So, which drives do I go for?

Ideally, they'd be 2TB, as I've seen a lot of enclosures that are only 4 drives (the G-Tech G-Speed eS for example - http://g-technology.com/products/g-speed-es.cfm) so want to maximise my available storage.

It appears that I'll pay a hefty premium for the 2TB Seagate Barracuda (http://www.amazon.co.uk/SEAGATE-7-2RPM-SATA-BARRACUDA-7200-12/dp/B003AM7QI4/ref=sr_1_2?s=computers&ie=UTF8&qid=1294271591&sr=1-2) as compared to the 1.5TB Barracuda (http://www.amazon.co.uk/Seagate-Barracuda-7200-11-3-5-inch-Drive/dp/B001IKKCLI/ref=sr_1_3?s=computers&ie=UTF8&qid=1294271591&sr=1-3) - over £56! - so I might be wiser to save some cash and make do with the 1.5's, but I'm VERY keen to get other peoples thoughts!

Oh, and I'm available to do a few freebie edits while I'm starting up! Drop me a line

Phil