RPM makes no difference, a 40 gig 5400 rpm drive was an option on the 2600 and I've used 5400 rpm drives in laptops a lot older than that one. However, I have my doubts about using a 60 gig drive. The only way to tell if you can use it is to install it and boot it up with your XP CD and see what Setup says about the unallocated space. if it's around 55 gigs, you are good to go. If it won't boot or shows less than that amount of space, there's nothing you can really do. I would also advise you use a better cloning tool than the WD DLG.
I have had issues trying to clone laptop drives with both of them out of the laptop and connected to a desktop IDE, if the desktop bios handles large LBA differently than the laptop you will have an unbootable and inaccessible drive when you put it in the laptop. I use my Apricorn USB housing to clone them - using the Apricorn software (which is OEM Acronis). I put the new drive in the laptop and the old one in the housing.
If you want to keep the 30 gig as a backup, order this up:
http://www.newegg.com/Product/Produc...82E16817155602
Housing and the software.