If you can print to the fax software (and it is part of your fax machine), then you can probably Fax to PC. Almost none only work one way. Go to the website and look at the info. It should be there. Are you able to see your fax settings using your browser. That's one of the nice features of a networked fax.
We have little problem with signatures either. Just to be sure, I changed all users to my name and just gave them their username and password. So, their names still come up in the dropdown list, while my signature shows up everywhere. It's a nice workaround, but you lose the usernames inside the messages. Small price to pay for having my name there.
UpDox is pretty cool. And, Andrew Barbarsh, CEO, is extremely accessible. You can email him. I am sure he would call you at midnight if necessary. He is incredible.
FAP is also still an option if you're interested.