i'd get the one with the faster hard drive. you'd be suprised how much it can affect your general usage of the computer.
I'd agree. My bias would be towards the A64, but the reality is that the HD is going to have a far bigger impact on your day-to-day usage than the processor. At that level of CPU, you're only going to see tenths of a seconds difference in most tasks, but loading files and programs is going to take seconds longer with the slower disk. It affects general usage, too, if you have enough loaded that things start swapping -- the fastest CPU can seem badly bogged if it is waiting on the swap file. I can barely stand a 5400 disk in a laptop (the next one I actually purchase with my own money is going to have a 7200). A 4200 would be intolerable.