I was playing Silent Hill a few years ago on BLEEM, and it play'd fine but the buttons on the original Dreamcast controller there is no enough as to the PSX.

What about using a PS to Dreamcast converter?
PS2 controller to Dreamcast adapter Total Control PLUS | eBay


Or some 3'd party controllers have extra buttons
Mad Catz Wholesale Lot Of 10 Dreamcast Dream Pad Analog Controller Madcatz Assorted Video Games Controller | eBay

Thanks