Snip
From: Jeff Oberg
 I have managed to source a 6' long, 6" thick, 23" wide slab of live oak. So my
next project is likely to be a Roubo style bench made of live oak. I'm not sure
where this is going to take me. I'm considering vice hardware for the bench.
…I get to building my work bench. 
Unsnip

If I may offer a bit of advise, build the bench first. Roubo is a great choice.
With a 6” x 23” x 6’ slab to start with solid will not be a problem. Will it be
perfect? Perhaps not. But it may be the first of many with each being slightly
more like what you really need. Currently I have four made to fit different
needs, mechanical, fabrication, machine tool, and wood working.
I recently completed a dedicated woodworking bench for my son and another for
myself. It makes everything else so much easier. Nothing like working on a
proper bench with proper methods to hold the wood in position.
Vise hardware is a personal decision. I went with leg vises on both. I like hold
downs for versatility but left the position of the holes up to Ryan for his.
The rest of the list will still be there. Mine has never gotten smaller. As you
skills improve your project list will expand at the rate of your families
imagination.