Matt,
Usually there is nothing wrong with a trainer on floats. Before you search the world for the best seaplane you should search for the best woman. You will die long before you find her and then you won't have to worry about the seaplane. The planes which are mentioned are all great but there should be nothing wrong with yours. What do you want it to do? Are you a accomplished flier or still learning, are you an accomplished builder, how much money do you have, where do you fly from? These are all questions which will determine the best plane for you.
I would suggest for you to get some help with the set up on your existing plane and to help you with those first few exciting flights off water. When you have done that you will be able to tell which is the best plane.
Keep at it.
Peter