I've seen those plans, they look nice, but not simple.
I used two pieces of 2x12 for the top surface, and a buch of 2x4's for legs and cross bracing. Put it all together with big long grabber screws. I also ran a 2x4 on it's edge down the back of the table to keep stuff from rolling off the back. My reloading bench is only about 4' long, but it's heavy enough not to rock and roll when I use the press.