eDrawings won't open .step files. The best bet is to have you open and save them as a SolidWorks file that can then be opened in eDrawings. However, it would be a 3D solid so your sales & electrical departments would have to use the measure tool to get their dimensions.
If they just need dimensioned drawings, your clients should send pdf's or dxf's of the drawings.
One option would be to add 3d Annotations to the model and save-as eDrawings. SolidWorks supports the ASME Y14.41-2003 standard. These 3D annotations are visible in eDrawings. You can also enable the measure tool (as Jeff mentioend) so that end users can measure anything you didn't explicitly dimension.