If I understood you correctly, newbie9618 - no you don't need business cards of your own for anything. The only time you let the CSR's / managers know who you are is for reveal shops and the MSC will provide you with a letter stating your purpose.
You should have a scanner at home. It will save you a lot of hassle. Check PLbell627's Kodak or HP Officejet all-in-One. I got mine last year for $50. You don't need anything fancy, but some MS companies will only accept scanned receipts, businessc ards, etc.