Hi Nathan
This scenario is very possible as the VPN simply acts to extend the functions of your network. Since the WinGate VPN passes data along the VPN tunnel it wont affect the actual data.
For the scenario that you described you will need two single user licences, as there are only two machines (users) involved in the VPN.
WinGate VPN is licensed based on the number of users on your LAN who will be participating in the VPN. (including one licence for the WinGateVPN machines at either end of the VPN)
The Printer cable type shouldnt matter as the machines are hosting a networked printer
Obviously if you expand the user size or number of VPNs then you will need to purchase more licences.
You can find more on WinGateVpn and licencing here on our website:
http://www.wingate.com/product-vpn.php
Regards
Erwin