I am a 3D printing specialist with good experience regarding converting Digital Elevation models (DEMs) to STL, repairing them, adding a touch to them and printing them
I use software package including 3DEM, QGIS, Accutrans, and Blender or Autodesk Netfabb or further model preparation
Thus if the task needed is close to this process I believe I can do it for you in a perfect way, and you can also send me task details to start working on things and show you some results even before awarding me the project or paying anything to be sure that your money will be going to the right engineer
Regards