I believe that virual box is able to handle the switching functionality. Try following along in this video:
. He does what you are trying to do. For each VM that will be on the same local network, he enables a second network adapter in the VM's settings, and attaches it to "internal network" and gives this network a name. Do the same for each VM and use the same name for the adapter on each. Think of the name as representing a switch that these machines plug in to.
Another option is to just attach the VMs to your physical network and let your real router assign IP addresses to them. I've done it that way in the past.
By the way, if you have Windows 8.1 or Windows 10, they now include Hyper-V for free. Hyper-V has a few more options for creating virtual switches. I used to use virtual box but I've switched to hyper-v as I found it to be easier and more reliable.