Creating A Pentesting Network Using Virtualbox

[riizu]

Hey, after taking a look through the questions, I found a few threads that semi-addressed this question, but not enough to do what im looking for.

Currently i'm looking for a way to create a fully private network in Virtualbox (which is simple enough with Internal Network) but also be able to emulate wifi interactivity. I currently do not have a wifi card with my desktop, so I was thinking a VirtualBox solution would be a great way to test things like WPA and WEP as well as any other wifi goodness.

Is this possible?

Also, it would be even better if there were a way I could have it so one of the machines (lets say the windows one) could actually gain internet access. For example:

---------------------
[                   ]
[       [Win] [BT5] ]  
[         |         ]
[ [Wireless Router] ]
----------|----------
       INTERNET      

Thus, the enclosed square would be the virtual testing enviroment, with 2 machines (Windows and BT5). Potentially a third because of the wireless router, but im not sure if thats necessary. Then, the Win machine connects to the router, which then gets it access to the actual internet, thus enabling it to create traffic for potential attacks by the BT5 machine.

I hope that all makes sense. The end result would be a network that can provide a real world example of finding a wifi network, gaining access to that, then running exploits against the windows machine.