You make a good point, but the Caviar Black has a larger warranty coverage period, and since he's going to be buying an SSD anyways (which'll be far faster than either HDD), an HDD with a larger warranty period will be a better buy IMHO.
Longer you mean, but I digress.
When choosing hardware I usually weigh performance, features, reported reliability, and efficiency higher than price (though price is important of course). Additional benefits (such as longer warranty) come as an extra bonus, and should not necessarily be a deciding factor.*
In my opinion the extra 2 years does not make a big difference. It has been my experience that every hard drive I've ever owned has lasted significantly longer than the average 3 year warranty period (I have drives over a decade old that still work just fine). In fact, I have given away more drives because I did not need them anymore than I have thrown out/destroyed drives because of failure.
Plus both 3 years and 5 years is a long LONG time in the computer world, by then platter drives for the average joe might be dying off with SSD taking center stage. Platter Drives might be 2-3 (or 5+ if Toshiba gets to the point of producing bit-patterned based drives at a consumer price) times the capacity for the same price, who knows.
I guess I'm just really lucky with my drives.
*A drive that runs cooler and more efficiently should in theory last longer, which is what I'm getting at.
I'd recommend the ASUS Essence ST instead; it delivers significantly better sound quality than either of those cards, with features like jitter reduction etc.
For speakers, I recommend the Logitech X540, M-Audio AV40 and the harman\kardon SoundSticks II (I've owned these, and they were awesome).
I've heard of the Essence being a very nice card, too bad they don't have a PCIe-x1 version, and that if you want 5.1 surround sound you need to use S/PDIF. I had the X-530s before I blew out the left channel twice, those were great speakers. I heard the 540s weren't as good (looked cooler though), but only by a small margin.