Re: board size?
Your skill level also plays a part in deciding which board size is best. I had a larger guy that was new to boarding, and struggled a lot on a smaller board. As soon as he tried my 142, he just about instantly progressed.
If you struggle at all with stability or getting out of the water, you may want to step to a larger board. But if you're already getting up and jumping wakes no problem, you're probably good with what you have. But yea, 147 is pretty big. You might consider something in-between too.