You can run RDP server on *NIX using xrdp. It uses X11 -> VNC -> RDP. If your Linux server is fast enough it can handle this, and VNC goes over loopback, so that won't lag the connection.

Keep in mind RDP usually doesn't support encryption.

You can also use NoMachine (NX) on the *NIX server, and use a NX client on your N8x0.

Plus the suggestions I provided here above.

However, Hamachi and LogMeIn are easier 'quick and dirty' solutions