Latitude and XPS: drive two monitors

Hi,

I'm evaluating Latitude series 5000/6000. I need to use the notebook with lid closed but with two monitors attached with extend mode. These models have both vga port and hdmi port, will they be capable to handle dual monitors?

I see that some models have only an intel gpu, while others have intel gpu + nvidia gpu. Do I need a dual-gpu model in order to reach my goal or is the single gpu enough?

Now think about the same question regarding a XPS 13": it has only a mini display port. How can I handle (if possibile) dual monitors?

Thank you