There isn't a way to specify units in the EPDM BOM.
So, I wrote an addin for SolidWorks. What it does is on file save and file save as, it takes the current model units and converts them to inches rounded to 2 decimal places and places that value in a "LengthInInches" custom property. You can then map that property to the BOM. I've attached the source so you can modify it to your needs. (As well as the compiled dll as is.)
Disclaimer: you bear the risk of using it.
SetLengthProperty.zip 1.2 MB