I build my lab MEG systems with:
With those settings it should install without any complaints. If you need any decent performance, increase the memory a bit, and add extra disk space. I can't remember at the moment what the VMWare limits are.
Does that answer the question? If not, what specifically are you having an issue with?
What mode do you want to put the appliance in? The modes and a desciption taken from the Quick Start Guide (for v7.0):
Which mode you choose will change how the system is placed in your network. My preferred method is the Explicit Proxy, as all internet traffic won't go down if the MEG does, but you need to choose what would work best for your network.
As far as testing spam through the system, check out KB article KB76608.