I'm building kitchen cabinets out of melamine covered particle board. I'm using the same design that Danny Proulx advocates in his book, Building Kitchen Cabinets. However, because I have a small kitchen with a high ceiling I'm building them taller for additional space. He calls for 3/4 or 5/8" stock. Since I can't find 5/8 I'm using 3/4. These things are HEAVY. I'm beginning to worry that they won't hold. I've thought about replacing the backs with 1/2 melamine. Am I worrying about nothing? I emailed Danny and he said I'd be okay, but I don't know....