Port forwarding limits you to a single local machine. You couldn't have an outside computer talk to more than one of your local machines, or have one outside computer talk to one local machine while another outside computer talks to a different local machine. That may not be an issue for you, but be aware of the limitation.
May not be relevant in your instance, but FYI:
You can port forward to more than one machine.
It is perfectly acceptable to have inbound traffic on port 8001 (for example) forward to machine 1 on the LAN on port 22, then inbound traffic on port 8002 forward to machine 2 on the LAN on port 22 etc.
This opens up possibilities if the client application is HTTP aware, and understands redirects.
using an example of having two web servers on your LAN, but only one real IP address:
It is perfectly acceptable to have inbound traffic on port 8001 (for example) forward to machine 1 on the LAN on port 80, then inbound traffic on port 8002 forward to machine 2 on the LAN on port 80 etc.
Using a redirection service you could forward traffic to http://www.My1stGreatSite.com
to your real IP address on port 8001 (machine 1), and traffic to http://www.My2ndGreatSite.com
to your real IP address on port 8002 (machine 2)
Using a service like http://www.dyndns.com
(their redirect is called WebHop Redirect) you could give every one of your machines on your LAN a DNS entry with the ability to accept inbound traffic to port 80 on each local machine. You'd add the records at http://www.dyndns.com
and the corresponding port forwarding in your router.