You have to decide if you wish to have plants that can be disposed of when freezing weather occurs.  Small shrubs look good but how do you care for them in the winter?  They cannot just remain outside in those pots as the roots will freeze.  That said, I am giving you a few links with information to consider.  Ask Extension: Can I landscape my yard with perennials in containers? (umn.edu)    Big Ideas for Small Spaces: Tips for Successful Container Vegetables (umn.edu)  If you are thinking about small shrubs, I suggest you visit a local full service garden center this spring and see what is available and would grow in a container.  A suggestion would be a tropical hybiscus.  You can bring that pot inside for the winter and then put it out again in the spring.  Trim it back somewhat when inside.