i have easier cheaper way
buy ps2 rapid fire controller , its like 10 pounds max - probably 5 pound or somthin
and buy a ps2 to ps3 adapter
plug them in to you playstation
and viola
this works coz i used it at my friends house
BUT the controller that he has has a button in the middle (like the start and select) and when you click it , as soon as you tap R1 all your ammo is gone . . . LOL
worth a trie tho