In Qlikview Server Reference Manual CAP 10 "Service by Service" you can see the ports comunication the service use.
It will really depend on what you want the QV Desktops to do outside of the firewall? Will they just be using Applications on the network or will they be building QV Applications and will need access to the Database Servers also? Also do not forget 443 if you are running SSL on your IIS Boxes. Also will you be running QV Web Server or going to use IIS?