|Remote desktop should be all you need. Once you've disconnected from a session, the PC you've connected to requires a login to get back into it. Alternatively, you could reboot it before you end the session and it would be back to the login after rebooting.|
As to how. First you have to enable Remote Desktop on the PC you wish to connect to. Then you need to create a port forward on the router at the destination. If you've done RDC in a LAN environment, then it's really no different across the internet except for need to know the external IP of the location you're going to be connecting to.
I would set the RDP up at home and test it on the LAN to ensure it's working before moving the box to the remote site. Once you have it there, assign it's TCP/IP settings statically. Then you need to create the port foreward on the router at the remote site. You will be forwarding port 3389 to the LAN IP of your target computer.
After you've got that ready, you'll have to get the external IP of the remote site. That's as simple as going to the "what's my IP" website from a computer located at the remote site.
Armed with the external IP, you then go home, fire up RDC and enter that external IP. If you've got the port foreward done correctly, you'll connect to your PC at the remote location.
I don't think SSH is going to be the answer for you. Especially if you plan on copying files back and forth between the remote location and your home.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.