Banner on the bridge with a phrase you provided, to be unrolled out from the bridge, by surprise, in front of your gondola
The gondolier will stop in front of the bridge with the banner, giving you time to propose
Musicians in gondola with you (accordion + singer, or guitar + singer, or violin)
Bouquet of red roses hidden in gondola, given you by the gondolier at the moment of surprise
Professional Photographer (total approx. 30 photo) starting from the moment of surprise, to follow the gondola until you get off it, and last photos of you taken on and by bridge with banner, to be downloaded in high resolution few days after event.