Antoine is absolutely right.
We prefer to go in February, the festival is amazing, and you get to experience the people and their culture - not just the island of stone faces. It helps you understand and give you appreciation.
Also, our winter is their summer. Some people say February (being the height of summer) is too hot to visit. I see you are from Panama - you will definitely be able to cope! I am Canadian and it was fine (and quite welcoming).
We experienced rain daily during our visits, but it only lasted 15-20 minutes (heavy downpour) and then the sunshire returned. Very nice. I have heard Christmas is quite nice there too, but I have not been.
In any case, I am sure you will have a wonderful time no matter what the weather, since Rapa Nui people are kind and welcoming.