WANTED: Big Driftwood for art installation needed

of a piece of driftwood. This driftwood would have to be big, flat and oblong-ish. So around 5 ft x 3 ft x 10 inches. The measurements don't have to be exact and neither does the shape. We plan to hollow the center out and replace it with a stained glass project (to be designed). Any help would be appreciated. If you have something like this or can point us to the right direction, that would be awesome. We know that we can find driftwood on any beach on Vancouver Island, but this particular piece might prove to be challenging to find. Thanks for reading my long request :)