Crystal Kluge creates beautiful calligraphy and has also created a custom font that is perfect for monograms (and in fact inspired by the custom monograms she created for clients). The font is only $29.95 and it includes 10 framing options. You could use one monogram on your invitation (just your first initials, for example) and then change the frame and use your married monogram for your menu cards at the reception. So lovely! You can buy the font here and here, and you can take a peek at Crystal's flickr stream for some more lettered inspiration.