I recommend semisans for getting small-run invitations made. Creative and friendly guys, great work.

plenty of inspiration here:
letterpress

There is a process by which type that you set on a computer or hand-render can be burned on to a photopolymer plate. The plate can then be put on a letterpress and printed in the traditional way . . . so just about anything you can imagine, can be printed (really fine lines can be difficult). I would find a local press and sit down with them. Many people who own a press today are artists themselves and love a challenge.

Hi Caco. I design and print wedding invitations. I design mostly unorthodox shapes/sizes digitally and then have either photopolymer or metal engravings made from film and print them on my Vandercook SP15.

Gimme your email address and I'll get in contact ... I can send you some examples, maybe those will get your juices flowing.

And when dealing with a very tactile technique like LP, remember: inks and paper are going to be just as important as what's on the page itself.

As for type: you can use almost anything you like, although I have a personal fondness (since I like really hard impression) for lower-contrast slabs and transitionals.

Hey thanks all for the replies. Great examples!!!
Joshua thanks too, you can email me at cacodesign@att.com. I would really like some examples of your work.

Thanks again all,
Caco