Thanks for trying to help, but it won't work. Sorry.
SIF files are a Windows-only format, which is semi-obsolete and somewhat discouraged. They can only be used on Windows Vsig – they can't be used on a Mac, nor understood by our hardware products.
This may sound harsh, but SIF files use a Microsoft technology that can only be found on Windows, so we can't do anything about it. This is one of the reasons they are discouraged. Maybe someone with a PC can load the SIF files in and save them as SIG and send them on.