Well, with VistaPrint doing 50 oversized postcards free (including own design upload) or 100 regular sized postcards free, I decided to make my own !
DH chose one in the 8 I designed. It's the one with the sunset. I attach all my templates for your usage. For the back of the postcard, you can do simply a blank back. I did a "waterprint" of the image by using the "recolor" option in powerpoint 07, deleted the words and added our monogram (cf the file called "back, without the monogram).
I also attach a pdf of how they should look. The fonts I used are :
Bradley Hand ITC
Tempus Sans ITC
The languages in the one that has several languages are Russian, Spanish, French, Hindi, English, and Bulgarian. This was done to adapt to my guests, it can of course be customized (just google what you're looking for).
Before uploading to vistaprint, make sure to have only one side per file (ie, one file for front, one file for back) and save the file to a pdf.
I hope this will inspire some of you ! Enjoy !