Well if they are illegal to buy here now, then the only solution I can think of is you coming over here to Ca and catching your own(which is also illegal). Or hope an lfs gets one in anyway. My lfs said sharks are out of season now so that may be why they're so hard to find.
It is not illegal to own or buy or sell leopard sharks. In some areas of the prohibit the catching of Leopard sharks under 3 feet. If you have the proper permits to collect leopards for the aquarium trade you still can collect them.
Jim
my LFS had 3 leopard sharks, in like a 30 gal tank but it was pretty wide. awesome looking sharks. good luck finding one and if you get one tell me all about it.