Hello,
I work with D3 a lot. Please, look on my ongoing and completed projects.
Also I have an experience in Basic Primitives replaceing from scratch and extending other graphing libraries (like Flot, Raphael).
So, I'm sure that can create any tree you want.
But final price will depend on how many methods you need, how flexible and how much error handling should be implemented (in case if you want to build API of your product, for example).
Would we, please, discuss it?
BR,
Andrew