LOTS of great suggestions. Thanks! I think I've narrowed it down to 4x4 legs and 2x6 frame - all of which I have on hand. I'm torn on the top. I have plywood and it's light so it's the easiest. The solid core doors sound like a great idea though. I'll mull that one over.
Pwd72s - Thanks for the book info and especially the Wilton vice story. It triggered the recollection that I needed one. Right after seeing your post I checked onine. Big $$. Then I checked Craigslist. Someone very nearby (which is weird because I live in the sticks) had a "5" Wilton listed for $50. I went and snagged it this afternoon. It's not an heirloom quality vice like yours, but it's damn good.