I'm afraid I don't have any experience with shark leather wallets, but a quick Google for "shark leather wallet" returns a good half-dozen promising sites, some of which look pretty nice.
They're not shark skin, but if you want a nice sturdy wallet that will last a long time, I can personally vouch for Fox Creek Leather. Mine has been carried every day for six years, and while it is starting to show some signs of wear, I suspect it has quite a bit of useful life left in it...