This is probably a little too late, but here's some recommendations for Dark Chocolate:
French:
Michel Cluizel - A dark roaster, One of my favourites. Their 99% Noir Infini will redefine what you consider to be chocolate, but isn't that accessible. The rest of their line is relativly accessible. I'd recommend the 1er Grand Cru range of bars (5 bars), to show how terroir can affect chocolate drastically.
Valrhona - One of the 'lightest' Dark Chocolate roasters. Their bars tend to be light, fruit and accessible, and widely available for the most part.
Pralus - One of the darkest, if not the darkest roaster. Great, though.
Chocolat Bonnat - Sort of middle of the road in terms of roast character, and pretty good.
Belgian:
Pierre Marcolini - A belgian dark choclate made in the french tradition - reputed to be great, though I haven't tried it myself.
Stay away from Godiva - Overpriced for mediocre quality. If you want that sort of "mellowed down", non-complex flavour, buy something from a coverture supplier like Callebaut - it'll be a lot cheaper.
Italy:
Amedi -mmmm.... good but expensive.
Domori - They make very good chocolate, that are often very different from other chocolatier's bars; I'd recommend not trying them as your first introduction to quality dark chocolate, but do try them sometime.....
That's off the top of my head so far. A good place to look for them would be
www.chocosphere.com, or your local gourmet food store.
Feel free to ask more questions!