Those needles are amazing. Love the look. The trunk needs some movement. Put a few bends in it.
Seriously, the long needle pines are difficult to create pleasing bonsai designs with, but it could be done. With this tree, I would consider going for a tall, gracefully curvy trunk. And then branches placed more like one would place branches of a weeping tree, except the ends of branches need to be pointed up, and the needles do the weeping. Think about how tamarisk is styled. Or weeping willows. It could work. Don't try to keep it to small, you will need some size to make it work.
Just a thought.
Definitely one of the more interesting and rare pinion pines. Cool. And if I remember, this is still a very young tree. How old is it?