Musical Stylings

So we decided to drop our search for the perfect wedding band (ie. one that plays Sinatra, Willie Nelson, Johnny Cash, Journey, and Meatloaf flawlessly) and decided to go with a DJ. We're having fun writing our Must Play and Do Not Play Under Penalty of Death lists. But the real musical question is what will we play during the ceremony. I have two possible soloist but I have no idea what to have them sing.

Any suggestions?