If you're having round tables at your reception, my favorite vessel for flower arrangements is definitely the footed bowl, or compote. They lift flowers up to the perfect height and create a lush shape that fills out the table. I made the arrangement above in one and you can see just how much volume it has. Here are a few great options:
Crate & Barrel's Classic Century Footed Serving Bowl, $47
Williams-Sonoma's Marble Footed Bowl, $249
Jamali Garden's 12" Brass Bowl, $50
Reed & Barton's Paul Revere Silverplate Bowl, $75
Sur La Table's Footed Glass Bowl, $30
Of course there are tons more on the market. Good Luck!