I want a plant that can be grown in full sun but can also withstand some frosty nights. It would be in a container, not easily moved. Something which is drought resistant and doesn't grow too tall.
Full Sun and Frost
Certified GKH Gardening Expert
Sounds like a potted Evergreen would be great for your zone and condition requirements.
Here is a link with some information and suggestions.
I would also have you contact your Country Extension Office to get a list of plant specific varieties that will be hardy to your region.
Here is a link to help you locate your nearest office.