This was using one of the smaller slabs (44" x 40") we seem to occasionally have hidden away in the corners. Smaller can often be more exciting wood. Really exciting wood is usually situated right next to a large anomaly in the tree such as a limb crotch, or embedded rock, or lightening strike. A wonderful metaphor for life on this planet. The best grain grows right up into and around the worst anomalies.
We work with five local sawmills from Portland out to Vancouver Island. Looking for something unusal? Our sawmill on Hawaii runs across oddball slabs and can usually come up with something with a few months notice. Again, you can ask for certain dimensions, certain grain patterns, certain colors, but the Slab gods don't pay attention to us measly humans. Be ready to consider options, none of which are exactly what you set out to find but will be strikingly beautiful in their own way.