What you posted is correct, but here are some other items to take into consideration:
rpm: the higher, the faster your hard drives reads/writes data. This in turn affects seek time. The most common rpm speeds you will see for IDE drives are 5400 and 7200. For the main hard drive in a PC, go with a 7200. The extra speed will help out. The tradeoff is you get a noisier, hotter drive. The difference is not noticeable, if you are just an average user. 7200 rpm drives cost more, however.
Regarding cache size, the only drives that I know of that offer anything other than the standard 2MB cache are the special edition Western Digital drives. Unless you need the extra cache size, I would stay away from those drives, they just cost far too much.
As far as brand, I personally have always stuck with Western Digital. My experience with their customer service has been top notch. IBM also makes good drives, but avoid the 75GXP line, lots of complaints. I stay far away from Maxtor, they seem like low quality drives, IMHO.
So, I would say look at a 7200 rpm drive for your main drive, but a 5400 rpm drive is fine for extra storage. After that, choose a brand, and then let your wallet decide your hard drive size.
Hope that helps!