WAMP is similar to XAMPP, but I have better luck with XAMPP. As for needing Server 2008 for something like this, that's overpowered and too much for this purpose. Windows XP actually does fine, I have a virtualized XP system running XAMPP right now, and it does a fine job.
The key is to definitely be sure that you are forwarding the port on the correct system, especially if it uses DHCP (I set mine to static on the LAN) and then also make sure that you aren't running into conflicts. If you're using Port 8080 for the general Port 80 rule, you'll have to change the Port 8080 rule to something else, say, Port 8081. If nothing else in your setup is assigned to 8080, you can ignore what I just said.
Also, when you use Port 8080, you may need to type http://myserversnamehere:8080
to get it to display the page correctly.