@cahudson42 I bored the holes in my sandwich top with a 3/4" power auger bit with the drill in a portable drill guide that kept it vertical and in a way a bit like a plunge router. The guide screw of the auger was dead easy to centre over the laid out grid points. The holes are dead straight and clean sided. The auger bit was new which probably helped. As stated I have three rows from an end vise running the length of the front as well as from the front vise and holes in the front apron to support long pieces as well.
I decided to make my own top out of white ash because I had access to a planer and jointer at my local college where I was taking an intro woodworking class. Trim and vice jaws are white ash as well. Everything else is built pretty much as jdege describes. A plunge router with a 3/4" spiral up bit really made quick work of the dog holes. Finished with Danish oil.
I’m building my second bench. I built the first years ago with wood from old machinery pallets – mostly oak and maple. Mortised the legs into the base, and pegged ’em with 1″ dowels. Of course, the legs warped a bit, but that made everything tighter and stronger. The top is 2″ thick Ash, one board cut in half and joined side to side. Wrapped a maple apron around the top, and I think I screwed the top from underneath to the leg braces. Solid. Over time, built a cabinet under for 3 drawers and a small cabinet door. Works for me.
I wanted the left edge of the jaw of the front vise to be flush with the left edge of the top, the right edge with the left edge of the left front leg. So the amount of overhang on the left depends upon the width of the front vise jaw. The width of the jaw is, at a minimum, the width of the plate that supports it, but it's normal to make the jaw extend a bit beyond the plate. How far? The more it extends, the deeper a bite you can take with the edge of the vise, when, for example, you are clamping the side of a board being held vertically. But the more it extends, the less support it has. I decided to extend by 1-12", which gives me a 2-1/2" bite, and which should still provide solid support, given that the jaw is 1-1/2" thick. This means the top needs a left overhang of 12-1/4".