Honestly, you'd have to mix games together. Dead Rising 2 looks good, but lacks some of the other things you want. The first game requires some timed quests and boss fights to get the full experience, working on getting my hands on DR2 so can't speak for it
L4D 1&2 are both a little linear, but multiplayer is supposed to be fun, however, you have a PS3 and no gaming PC so you can't get them. Nor do you seem willing to branch out into the possibilty of Microsoft. If you really wanted you can find a cheap X360 for some good exclusives, but honestly, get a game comp. Steam is worth getting on it also, and if you wait long enough you can find some good games are great prices w/ free DLC.
PS3 zombie games, only thing I can think of is Burn Zombie burn from PSN store, but it's a small map with your basic assortment of weapons, the big twist is using flaming zombies as multipliers when you kill others. Unless you're willing to branch from Sony (which I do love, btw) you're going to be very limited on material to play to your specifications