I think you will be using your 17-40 and 430EX most for the indoor shots.
Group shots before going into the room (assuming at the registry of marriage), some scenes of the inside the room, the officiator, pics of the couple, couple signing , expressions, esp tears of joy etc.
Will be good if you have some flash modifier such as the lightsphere, bounce card etc, Else, can attempt bounce flash indoors if ceiling is not too high
For outside, you still might need some fill flash, depending on time and weather conditions.
For individual portraits, think ur 85mm f1.8 will be good, but dunno if you have enough time to switch around
Good luck, have fun