GoodReader and accessing multiple Macs

I use GoodReader on my iPad to remotely access my Mac files. It's set up as a SFTP Server on Port 22 and Port Forwarding is set up on my AirPort router to direct those connections to my Mac. This works fine but I have an additional Mac on the same network that I would like to access remotely, as well. I can set up a new SFTP connection in GoodReader with a different port and also configure my router for the correct port forwarding to the other Mac, but I'm having problems with Mac's built-in firewall not allowing the SFTP connection through this new port. Any suggestions? Does the AFP or SMB Server connection option in GoodReader work the same as SFTP? If AFP or SMB is an option which, port do I use for Port Forwarding? Thanks