Convert STL Scans to STEP

I have a set of 3D mesh STL scans that now need to become fully watertight, editable solids for manufacturing. The end result must be a high-detail STEP file that opens cleanly in Fusion 360 without faceting or faulty surfaces, so I can move straight into CAM and tool-path generation... (Budget: $30 - $250 AUD, Jobs: 3D CAD, 3D Design, 3D Modelling, 3D Printing, 3D Rendering, CAD/CAM, Fusion 360, Solidworks)