In my testing it appears the best format in this case is as *.igs format.
Hopefully the SolidWorks user understands how to use SolidWorks.
They will almost certainly want to disable 3D Interconnect in SolidWorks before opening the file.
Additional information:
There is a known issue in SolidWorks opening Autodesk exported *.stp files - the manual fix is to edit a single line in the export, but I forget what it is and didn't bother to search since the IGES (*.igs) worked.
ACIS (*.sat) also worked - but translated as a single multi-body *.sldprt file rather than as assembly and parts. This may or may not be desirable in this case.
Inventor format (appears) to be working, but translation is taking a long time - so I will probably kill it before completed since the IGES format worked. (I could have set certain Options in SWx for faster translation, but I left on default.)