I vote to get a 20" planer or bigger, spiral head is nice and a good agressive random orbit sander and a good hand belt sander. I have RBI drum sander which I gave up on. You can only take off 5 to 7 thousands per pass and you run a small knot through it still ruins the paper. It's so pathetic that after taking a pass the board heats up a little and you can't lower the head at all without burning. Maybe a dedicated drum sander with a way bigger drum and slower speed might work. Steve