Been reading through the past posts about building one of these racks, and I think I'm going to give it a shot. I'm not really that handy, but I'm cheap and I want to save the $$. Thinking about making mine 20" x 20". I'm wondering about the feet though. What do people put on the bottom of the rods? And is it possible to put casters on the feet, so I can roll the unit out from the wall to make connection changes etc? Or is that just not done?