Yes it is possible to monitor both hypervisors using same services and even same/common base of Management Packs. When license contains both hypervisors, setup will allow importing of all management packs at the same time. Also you will be managing both MPs from the same UI.
With respect to a trial license - could you contact our sales department? I'm sure they can provide you with a single license for both hypervisors. I'll check why we don't have a merged license on the website. Sorry for the inconvenience.
Let me know if you have any other issues.