Yes! You can create as many Resource Types as you wish (Firewall, Server, VM, Virtual Interface, etc.) and customize the fields that you care about for each Type. For example, you may not need to track the console port for your virtual firewall, so you would simply not use that field for the "Virtual Firewall" Resource Type. This way you can still track the console port for your physical firewalls like normal.
Create a new Resource Type from the Types sub-tab under the Resources Tab
Customize the Customizing Fields for your Resource Type. Now you can add New Customizing Fields of different types (text, dropdown, text area) and also use any existing fields that are available. See the Customizing Fields page for more details.
You will notice on this customization screen, you also have an area for "Gadgets". Gadgets are areas of additional functionality that can be added to the UI of a given Resource. See the XML Specifications page for more details.