evergreen tree

hi there! Im new to this site (and gardening!!) and Im looking for some help please!
Ive just got round to sorting out my back garden which is a patio, and to start off with, was looking at getting an evergreen tree to be kept at about 5 or 6 ft tall in a container?? Are grafted trees a good buy?

Any recommendations at all please? thanks very much

 

Rhinegold - a lovely conifer which keeps small, I have had one about 20 years and now about 5 foot, it has a beautiful gold colour which changes from winter to summer.

 

To that excellent suggestion - I would add, variaged holly - like silver king.