Virtualbox is good enough. But it lacks the fullscreen feature
You need to install "guest additions" to get adjustable window size including fullscreen.
In "devices" choose "insert guest additions cd image". Depending on your host operating system, it should find the cd image itself, otherwise you will have to hunt for it. Guest additions is included with the virtualbox download.
Best scenerio is using a linux host and creating your VB operating systems. Even using Solaris as a host OS is a good solution if it supports your hardware.