The Pearl uses a normal SIM card. For the phone to work properly it should have the 64k SIM card and the card should be the most up to date version from your carrier.
SIM card are general with the purpose to make identify a subscriber into your mobile devices provider. Any SIM card distributed through your arrangement will be work.
The type of SIM card depends on your cellular provider. In most cases, you should be able to use a SIM card from the same cellular provider in the Pearl.
Well like a lot of other phone the Blackberry Pearl uses a micro sd style storage card. They can be purchase from a lot of place. Be sure to check the maximum capacity that your phone can use so you don't but one that is too big.
Depending on your phone compay, you may not need a sim card at all. Remember the sim card generally comes with the phone. For example if you have a T-mobile blackberry, you will need a T-Mobile sim card.