I've had problems with external Seagate drives in the past. The drives themselves are fine, it's the enclosures that would fail, though that was a few years ago now. I imagine things have improved.
My personal favourites are
Glyph and
G-Tech
DV50 is 50Mbps, so theoretically you can reach 16 DV50 streams with FireWire 800, although in practical terms you won't get as many as that.
Alex Elkins
Twitter:
@postbluetv
http://www.postblue.tv
Post Blue showreel
Latest work:
Greyhounds in Motion at 500fps
My Vimeo Pro page