Forget it. They are a waste of money and of little benefit to you, particularly when you are starting out and need to spend money firstly on stock and secondly on display. Unless you are a limited company you do not need headed paper. Simply set up a master on the computer and print it as part of each letter you send. If you are VAT registered, remember to include yourVAT number on all letterheads.
When going round trade shows, suppliers will ask for your business card but it is not necessary to go to the expense of having these printed – they are of no benefit to you. It is quick, easy and more cost-effective to write down your details or use sticky address labels.