I love this idea for an arch! Just use two really old doors or else just buy doors and distress them (good project for me) and then connect them with a piece of ply wood so it will stand; then cover the wood with flowers or babies breathe!
For the Arbor: Something subtle like this with fabric. The fabric should not be over powering the chandelier. country wedding alter ideas Rustic Wedding Altars NH New Hampshire sticks and wood, with curtains and flowers- arch