Gavin told me in a PM that this rock would actually be used for a root on stone plant (as opposed to a root over rock I infered earlier). So I will share with you my response, so that anyone can respectfully (or disrespectfully) disagree with me. Most of us are here to learn anyway.
In doing a root on stone planting, I think that the most important aspect (artistically) is finding a plant that has some contrasting element(s) with the rock. For example the flat, scaled bark and longer needles of a pine would contrast nicely with the texture of your rock. On the other hand, the tight, dense foliage of a shimp would be, in my opinion, too similar to the rock.
You should also consider the color of the trunk, so that it does not match the color of the stone. If the colors are similar, that's ok. You can use moss to help the eye differentiate between the stone and the plant, but they must not match exactly.
. Can any one find me a 19inch/9inch/3inch pot that would be wonderful
