Portulacaria afra is a fun tree, watering/drought forgiving, can be wired, denuded periodically (spring) either to reduce leaves to smaller uniform size or to re-shape canopy. Buds back just fine. Likes lots of light indoors/sun outdoors. Can be held in small pots.
Since the branches are thicker, you will not be able to develop the fine type of ramification at the canopy under-surface, but you can still get a tight bonnet with nice looking, interesting, internal architecture anyway. You may want to reach in and make some white space by removing internal branches. Carefully, trace those branches that are in congested areas and remove those that don't have leafs at the surface in favor of those that do have leafs that are part of the exterior/canopy, keeping in mind that when you have two branches in the same area and like one better than the other but it's not as well placed, they wire easily. They grow straight branches, but can be re-directed by clip & grow by cutting back to a bud pointed in the direction you want the branch to continue.
You can also create separate clouds instead of a single, contiguous canopy by taking the opposite choice by reaching in and removing the taller branches in favor of shorter branches making a new, lower canopy on one side or another.
You have a tree with lots of options because there is so much there: do nothing but clip off anything that protrudes beyond your imagination's boundary of where you want it to stay, or let it smoothly expand , or do either of the two options above! Nice buy! Good decision...