When you say they come in 15", etc......what is that the measurement of? Throat plate space? And, I assume the throat plate space is the distance between the needle and the opposite side of the machine where the quilt is held while sewing? (As you can tell, I am new at this "quilting system" information.) Been sewing and quilting for years, but don't know about all of this.
And thanks for the picture of your set up. Nice and roomy place to quilt.