I am not familiar with ePOE. It is not an open standard. I presumed you were speaking of regular POE. EPOE appears to be a proprietary technology used by Dahua so if that is what you are using, that might actaully work for your needs.
That is not a booster but a Ethernet to VDSL converter. It does not appear to have to POE capabilities so it looks like you would not be able to power a camera over it and you would need power for the box on the far end.
Ethernet over copper is only rated to about 320 total. It will run further even out of the that spec, but 750' is quite a stretch. This will likely not work for a reliable network connection.