I'm a cocktail snob, but I like the idea of an espresso martini; that's a surefire crowd pleaser. If you want something a little more interesting but very much in the same vein, I'd recommend The Revolver: 2 ounces Bulleit bourbon, half an ounce of Kahlua, a dash or two of Regan's orange bitters, stir with ice for 30 seconds or so, strain and serve up with a flamed orange peel garnish. It sounds odd, but it actually tastes similar to an espresso martini with the sweet coffee flavors from the Kahlua stringing together nicely with the spiciness of the bourbon and a slight orange note from the bitters and garnish. Great drink.
As far as light beers, is there a beer store with fairly wide availability near you? It's a long shot, but The Commons brewery in Portland, Oregon does an
Urban Farmhouse Ale that is simply spectacular. Maybe a bit spendy for a crowd ($9 a bomber locally), but worth picking up and sharing if you can find it. If not, maybe a blonde ale? Not terribly exciting, but they're generally pretty easy drinking, and it's more novel than Sam Adams.