Michelle,

First off. Beautiful plant.

The pot type/style you choose is first most a personal choice for your specimen. Depending on where you reside and whether the plant is actively growing will effect whether Now is the time of year to do repotting. Although it can be done during off times, the plant will recover much better if done when in full growth.

When you do repot it. You will need to examine the root structure and this will also determine what size, depth of pot you will use. Root pruning can be done, but I would not do this on your plant.

I was told once by a Bonsai enthusiast to:

The general rule of thumb is that the pots depth should be equal to the diameter of the trunk just above soil level.
For oval or rectangular pots, the length of the pot should be 2/3 the height of the tree.
For round pots, the diameter of the pot should be 1/3 the height of the tree.
For trees with especially wide canopies a wider pot can be necessary and this can be compensated by using a slightly shallower pot.
As equally, a tree with a very thick trunk (in comparison with the height of the tree) may suit a slightly deeper but narrower pot.

I would prune your plant if it where mine. The “Pruned Height” would be the one used for determining pot.

Prune after re-potting and once it acclimated to new pot (2-3wks.).

My personal preference w a plant such as yours is to have the widest part of the caudex just at soil level and not having it look like a ball sitting on top of the soil.

Hope some of this helps,

Rick