Blender Model Edits to STL

I have an existing 3D model that needs a tidy round of surgery in Blender (or Meshmixer if you prefer). Two separate versions of the file are required when we are done, each saved as its own watertight, print-ready STL... (Budget: $30 - $250 AUD, Jobs: 3D CAD, 3D Design, 3D File Scaling, Slicing & Print Preparation, 3D Modelling, 3D Print Design, 3D Printing, Blender)