The only thing like that at all that I know of right now is the Stein deSign Picturesque presentation case (the 24x36" size). (And you're probably looking for a "presentation case" rather than a "portfolio" if looks matter.) It's available at a number of online retailers if you can't find it locally. The lowest current price I've seen is $US 100; MSRP is $US 349.

The problem is size, and you're about twenty years too late for a lot of choices. It's not very often that people who want to see a portfolio want to see what is essentially a full-sheet (watercolour) work; they're more likely to want to see reduced-size reproductions. I believe the quote in vogue a few years back was, "that's not a portfolio, it's a gallery."

Roughs and comps are usually sent about as digital files these days, and camera-ready original art (and finished work) is generally shipped in tubes or packed flat in a sturdier, but more utilitarian, container (generally multiple layers of cardboard with hardboard stiffeners, or for more delicate grounds, in a wooden crate). The need for a graphic artist to carry large works around is small, and usually doesn't involve client interaction anymore, so there's little need to spend money on anything impressive if cheap plastic does the job.

It may be too close to your meeting to have a custom case built, but that's always an option. Any competent saddler or cobbler ought to be able to make you something very much in the Coach or Hermes vein (at nowhere near those prices). Or you might consider something made of bookbinder's materials. Linen, or at least a linen-look fabric, over hardboard with a moiréd silk-ish "endpapers" would look absolutely top-notch, would require little besides a good knife, scissors, some PVA glue as adhesive and sizing, the board and fabric, and a bit of time and patience. Just ideas, you understand.