OK, a sawmill relatively nearby to Austin can cut me a slab of 4-6" thickness in the size I'm looking for ~8' long by ~24" wide. In pecan.

Now, the question comes to how thick and how wide do I really want it?

Seems like folks have had different experiences with holdfasts in thick slabs. So... again, how thick do I want this sucker? And how wide. I'm thinking 23" or 24" My current bench is 20" wide, and I find that to be too narrow.