I have no idea about weddings,but consider a F/1.4. Usually F/1.8 lenses,the very cheap ones,don't offer a very pleasing bokeh compared to their more expensive cousins.
I am considering a Nikon 50mm f1.4 D for my D80 That is not a "cheap" lens, is it? I have played with it and really like it but the 50mm on a cropped sensor is kind of restricting. I was thinking about the 35mm f1.8 that was just released.
How is the bokeh unpleasing in the cheaper lenses? Are you talking about the circles in the background?