Sony Playstation Games Solutions - One of
the Largest Games Source for PSone Cheats, PSX Codes, Hints, Tips,
Walkthroughs, FAQs and Games Strategy Guides.
To gain the Ken+Ryu vs. Bison option, you must finish the game
without losing a round on the hardest difficulty. Set the timer to 25 sec.
and change it to one round matches, this would make it easier.