I'm sure there are companies that can organize your trip, tour operators or travel agencies - in Italy they are called "Agenzia Viaggi". I am not sure if you are asking for a company in Venice or near where you leave. Personally, I live in the US, but I grew up in Venice, so every time I go back and visit I basically stay with family and organize my own trips. I'm sorry that I can't help you. I would search for "Agenzia Viaggi Venezia" and maybe contact a few of them and see what they can offer.