I am building a chest on chest and the sides measure 21 wide by up to 38 high. I am joining 3 boards together to get the width. After running them thru the jointer and the plane, I realize that there still needs to be some smoothing. The #4 that I own is 9 1/2" in length. I see that there is a #6 fore plane that is 18" long and a new model bevel up jointer plane that is 22" long. I could really use some advice on which type of plane will work the best for my project. I am fairly new to the use of hand planes.