Weddingbee boards

I have a Manuscript fountain pen -- it works well if you're clumsy like me and are worried you'll get ink everywhere with a dip pen.  In general, Manuscript and Speedball both provide reliably good calligraphy products, so I hear.  The drawback with the fountain pen is that the catridges don't come in a huge range of colors (just black, light blue, dark blue, green, red, etc.) and the ink isn't waterproof.

If you're graceful and have the time for lots of practice, I'd say go with the dip pen -- India ink comes in a ton of colors and is waterproof.

I wouldn't recommend the markers.  The tips get blunt really fast (then they write like ordinary markers, without the sharp thin/thick contrast).