WD Caviar Green are not the fastest. In fact, quite the opposite. They are, however, cool and quiet from what I hear, but have some build issues, as my friends (and online reviews) can attest to.
With that said, WD is the way to go.
I see after a quick look your rack has fans, this is good, as well as a JBOD arrangement, also good. Sadly however, it appears as if your rack doesn't support RAID

, and also doesn't have eSATA, which really is fine in the end, given what you want to do with it. Also of note is the fact that your rack looks pre-configured with Seagate 7200RPM 32MB Barracudas, something I'll address below. If you really want high performance, you need eSATA and a Mac Pro, but with plain storage in mind, and possible light editing, FW800 will do the trick. RAID would really be nice though, especially RAID0.
As for the HD(s), I'll just leave my thoughts on a few below...
-WD Caviar Black 7200 RPM 32 MB 1-2TB (SATA II)
Highly recommended; I've heard nothing but good things about these drives, they're fast and powerful (dual platter), and for their size really move. They do heat up some, and do make some noise however.
-WD Caviar Black 7200 RPM 64 MB 1-2TB (SATA III)
This is newer. Look on newegg to find it, note however its SATA III, which is probably not supported by your rack. These drives are supposed to be wicked fast in a raid setup, but once again, you'd need eSATA to enjoy it. I wouldn't recommend this yet though as its still new.
-Seagate Barracuda .11 or .12 7200 RPM 32MB 1-2TB
I can't say I'd recommend these. SG drives used to be quite good, but recently the .11 and .12 revisions of the Barracuda have been quite the opposite, with the click of death really being prevalent in a lot of DOA or delayed death situations. I'm not entirely sure they worked out the problems in the .12. If you get higher end SG drives, it shouldn't be a problem.
-WD RE3, RE4, AV, or AV-GP
Not recommended. Reliability and/or overpriced.
-WD Caviar Green
Already covered.
-Hitachi Deskstar 7200 RPM 32MB 1-2TB
Mixed reviews here, but I would say an overall recommended. I have heard of possible build issues, but that's mostly from the Internet, and you know how that is. I would recommend the c revision.
-Samsung Spinpoint 7200 RPM 32 MB 1TB
Haven't heard anything bad about this drive-- but I'd do more reading in on it.
Beyond that, its no mans land.
If you want more performance over storage, go WD Velociraptor or the equivalent, or go SSD
