no, strictly the Hard disk types, amount of RAM or chip types are not strcitly about clock speeds.
However system speed is a rich tapestry where limiting factors and bottle neck may appear at any point.
And ultra fast processor is of no use whatsoever if it wastes more than half it's clock cycles having to shift information from the Ram to the HDD (especially if it is a slow ATA66 HDD drive).
At the end of the day, I'd still opt for the AMD option, simply because that leaves more cash in the pot for sorting out other limiting areas of a system, (most notably RAM).
If money was no object, they I think I'd have a Duel processor system (duel 3Ghz Pentium Itaniums) with 2Gig of Ram, zipping along with a nice 256Mb Graphics card, a nice array of raid stripped scsi disks for the ultra fast bus and ultra fast access times...
However it's a fact of life that money is a limiting factor...