Here are 4 places to get some awesome weapons:
The first is in the Paradise Plaza, if you go to the second floor, and go into the restaurant with the orange juice. Right next to the orange juice is the balcony, jump over there and you will land on a orange platform thing, there is a katana on there, which is good for slicing zombies up.
The second is in the Entrance Plaza, if you go up the stairs to the second floor near the main entrance, there is a antique store there. If you go in and to the back of the shop, there is a cabinet on each side, smash both, in one of them there are battle axes, and in the other katanas (as many as you want!).
The third is somewhere in the Alfresco Plaza, there are two shops here with awesome weapons. There is the tool shop, where you get your chainsaws, hooky things, sledge hammers and spades, the other shop is the gym - there are weights there that are good at smashing zombies out of the way.
The last is in the Northern Plaza, some where on the wooden platforms is the one and only, the drill! Good at drillin' zombies and throwing them at each other!
[more cheats for Dead Rising here]