@Drakes & Ire: The zombies here spread the infection through a bite - using melee primarily is a great way to die. Said zombies can only be dispatched by a headshot, so any melee weapons would have to be capable of one-hit decapitation or cranial penetration. Also, consider how hard it would be to get your hands on Japanese battle-ready martial weapons- hence why my character has a couple of weapons that are widely found, with common ammo. Dragonrider also got that down pat - M4 carbines use the 5.56x45mm standard NATO rifle round, which could be found in any military armory; and combat knives can be found in any Walmart.
@Drakes: Odds are, most of the rich people's money would have been tied up in stocks or at the bank, so it would be as good as gone in a Class-4 (global) outbreak. Also, you only need 1-2 knives, as throwing them is pointless and you only have the two hands.
@Ire: I like the Luger, it's a good survival weapon. The katana and Su-yari, though, those would be difficult to find. Though the Yari looks like it was designed for zombie killing
. If you really like the idea of a sword-style weapon, consider taking a machete- easy to find, and highly durable.
@Dragonrider: The date is in the future, yes, but after an extended outbreak which is set to begin in 2010 - only a few months from now. Any technology would have to exist now, right this very minute. As for weapons, like I noted, the M4 is an excellent weapon - just be sure it's set to semiautomatic or 3-round burst, not full auto.
General note: The idea is to mostly avoid conflict, with quick, silent kills when possible. Weapon choices should make sense. Ask yourself:
Do I have this weapon already (in real life)? Could I get one easily/legally?
How well does this weapon perform? What are its limitations, i.e. range, penetration, accuracy, noise, weight/commonality of ammo?
Would my character know how to use one? (i.e. a computer technician would be useless with an M16, a hunter couldn't use a katana, a soldier wouldn't know what to do with a bolas)
What I intended to communicate is that ammo will be heavy, so you'll need to be able to replenish supplies in the field.
Some weapon ideas:
Any .22 Rimfire weapons. Common and lightweight ammo, straightforward and easy to use.
M4 Carbine: Any military base would stock ammo for it; impressive penetrative power, accurate enough for headshots.
AR-15: Semiauto rifle variant of the M16; can be chambered for the .223 Remington rifle round, used in hunting and carried in many hunting and gun stores.
AK-47: Illegal, but also easy to obtain on the black market. A rather powerful assault rifle.
Glock 17/19/34: A series of pistols that use the common 9x19mm Parabellum rounds, with decent penetration.