There are a number of companies that make beautiful Christmas cards. One can get great cards from '123 Greetings', 'Card Store', 'Christmas Cards Direct' and 'American Greetings'.
Beautiful christmas cards can be hand made yourself or sold at many retailers. Hallmark and American greeting are popular brands of cards.
Christmas cards can be bought whole sale at http://www.dollardays.com/wholesale-christmas-cards.html. This online store offers a bulk supply of Christmas cards of various designs.
There are a lot of places online you can buy them. Try Zazzle, Clintoncards and Greetingscards. They have a wide variety of beautiful Christmas cards.
Christmas cards with Santa Claus on them could be bought at almost any local store. For example: Walmart, CVS, Walgreens, Publix, and many many more places.
Usually, cards are very sincere if you take the time to make them yourself. If you buy some glitter, Christmas themed stencils, markers & colored pencils and some construction paper, you could make a very beautiful and sincere Christmas card.
Hand made paper Christmas cards can be bought at the Hallmark store. This store offers a wide variety of paper cards, both hand made and made by machines.
Victorian style Christmas cards are very beautiful and can be more of a centerpiece then just a card. A few places to purchase these cards are Grandmas Attic, Pumpkin Hill House, and Victorian Trading Company.
There are many sites online. You will find multiple sites for your particular needs if you research them.
You may be able to find Irish Christmas cards at your local greeting card and stationery outlets such as Hallmark. In addition, there are a number of sites available online that carry a variety of cards including Amazon.
http://www.shutterfly.com/cards-stationery/Christmas-cards This will directly lead you to shutterfly's Christmas card section where you can order online a lot of Christmas cards.
Handmade Christmas cards can be purchased from many places. A few online websites include Pinterest, Amazon and eBay. Some schools have children make them and then sell them at school fairs etc to raise funds for the school.