recreating existing surface with equilateral triangles.

hi everyone 

I want to recreate an existing, free-form surface using equilateral triangles. I tried lunchbox, but there is no way to control the triangle sizes, and they are uneven depending on the curvature of the surface. 

I also tried simply making an equilateral triangle and mapping it onto the surface but i couldn't control the gaps which resulted, especially since i couldn't even divide the surface into equal parts. (again because of the curvature) 

my goal is to define a method to fabricate the surface using prefabricated triangular surfaces of equal dimensions. so, If there is any method to control the triangle dimensions and still re-create the surface, it will help. 

i have attached a jpeg of the surface shape and the resulting multi-dimensional triangles which lunchbox gives me. 

thanks guys