Research, Research Research!!!! We live in New York and recently got married in Italy and the biggest headache we had was the wedding planner. We used Ben Singleton from Italy Weddings as our planner and he was the antithesis of what the wedding planner should be.

We used Ben as a recommendation from some friends that had used him a few years back. I think the success has gotten to his head as he was awful in everyway. He was obnoxious, rude and had no interest in listening to what we had to say. His primary concern was his vendors. 
 
Given the timing of the wedding we were at a crossroad whether we should cut him loose before the wedding and now I wish we had. We ended up limiting the things we wanted him to do because he was being so difficult and even then he managed to get them wrong or I would say in some cases deliberately jeopardised them because we didnt do it his way.His wife was incharge of decoration, again we agreed everything on email but she did not follow what we had agreed.
 
We chose not to use him to officiate our wedding so he decided to be extremely rude to our very sweet celebrants, they were so deeply offended they wrote us a long email after the wedding to explain all the things that he had done and said to them.
 
He offered no assistance in the way of wedding planning and on the day he approached us numerous times to ask us silly questions, as the wedding planner he should have taken care of these things rather than interrupting our day. I am still shocked that a wedding planner of people would try and ruin your special
 
Hope this helps to provide some color. I would definitely advise taking time to find the right wedding planner if you definitely feel you need one. In hindsight the caterers carry out most of what you need so I would probably have gone without. Planning a destination wedding is stressful enough but when the wedding planner is the one causing the stress something is definitely wrong!