On the Transcend I was taking my spins bigger than ever before...like surprising myself! The swing weight didn't make any difference at all, not even on flips, and the board I normally ride is a considerably lighter.
I would go for the 142 if I were you. Since the board is a little slower, some extra board in the water should speed things up a little for you. I think it will help balance your height also. I'm 175lbs and the 142 was perfect for me.