You should only be ordering from Apple if you are a moron.
it takes PC100 or PC133 168pin 3.3v SDRAM
It has two slots, that is 512MB per slot.
*Edit
It takes the same type of RAM as your Quicksilver. cept the QS is PC133 and the iMac is PC100.. but it can take 133 so go for 133 incase you ever need to put it in a G4 tower later. Saves hassle.
it takes PC100 or PC133 168pin 3.3v SDRAM
It has two slots, that is 512MB per slot.
*Edit
It takes the same type of RAM as your Quicksilver. cept the QS is PC133 and the iMac is PC100.. but it can take 133 so go for 133 incase you ever need to put it in a G4 tower later. Saves hassle.