I've found American Blinds & Wallpaper (which have been cited in the other two posts above) to be a great online source for wallpaper. Their search engine is much better than any of the other online sties. Another suggestion - give yourself a budget to order samples as you narrow your selection. (For instance, I gave myself a budget of $50 for samples) It's amazing how different something may look in person that on your computer screen. Seeing the actual sample assures that you'll be happy with your final order.

I'm still not getting a sense of your style...what is drama to one person may be crazy to another. I'd suggest searching in houzz for wallpaper and foyer in photos and see what might appeal. If you're going for modern drama then a large graphic may suit you. But keep in mind that it's not just the color but the level of contrast between the color and the background that's going to count in terms of how 'disturbing' the pattern is. If you're looking to warm up the area, then a woven texture could be what you want. This is an example of vibrancy driven by the boldness of the graphic design, the repetition of the pattern and the color contrast. It's certainly dramatic, though I couldn't live with it. And be aware that some papers really speak to a specific style be it asian influence... ...or traditional...

Do a google image search. But your best bet is to just go to the paint/wallpaper store with this photo and ask them. It may not be made any more, but there are jillions of designs that may be close and in that style. Plan to spend a lot of time thumbing through catalogs.

I like the 2nd one by far the best, though all are nice. It just seems to make more of a statement, and hard to see but it appears to have a "gold" flower that would appear in the pattern occasionally. I could see highlighting that with the chandelier you select...such as something shown in the 3rd photo from Maureen. Hoping you do have some nice outdoor light coming through. I love the navy, but ideally maybe find something navy with a "hint" at least of beige or your green as in your other rooms. A historical toile would be nice. Anthropologie has a very cool mural that might work too. So many choices, right?!