So over the time playing the zombie maps I have accumulated many ideas. My first Idea is that there should be an unlockable area in an outdoor map like shi no numa nicknamed "the garage". Why? Because inside the Garage would be a tactical anti-zombie jeep. It would have a spike log tied to the bumper with rope, a mounted .30 macine gun on the back, and supped-up engine for off terrain roading and extra armour that the zombies can tear off, but you can repair. You could only drive the jeep so long though, as it runs out of gas, so you have to turn back and buy more gas at "the station". There would be a driver seat, a passanger seat, a gunner, and the fourth guy would huddle in the back in front of the gunner. The two passengers would be able to fire their primary weapons while riding in the jeep.
My second idea is alternative melee weapons which could be bought off the walls. I mean lets face it, your knife becomes very useless, very fast, and if you run out of ammo, you want something more....solid, to make a stand with. So I was thinking that you could buy a tomahawk for 1200 and a machette (sorry bad spelling) for 1500. Or some price around there.

So the difference would be that the tomahawk would by slightly heavier (so you move slighty slower while moving and slashing. Also it would do more damage, but the time inbetween lunges would be greater. It has greater "swipe range" too. The machette would just be like the tomahawk only even more so. More recovery time, more damage, more range, more damage, even slower movement.
Also, it would be nice if you could by some kind of zombie deterant. Like tabun gas that stunts them (but can also stun the thrower if thrown too close).
Also, some more perk ideas....
Extreme Conditioning 'Gatorade'(subject to change due to trademark issues

- Run longer. If you are unaware that your team moved on to the next hut, and you need to run to catch up, or you need to quick grab a gun off the wall, being able to run longer would be very useful.
Agility Ginger Ale- When desperately trying to run through a horde of zombies, you get don't get block as much. Essentially, you can go through half of a zombie, although it will be more like pushing zombies out of the way a little bit.
Deep Impact Coffee- So that you can shred through zombies in a literal sense, or shoot through wood.
Sixth Sense Potion- You gain the ability to sense when zombies are near (Kind of like Frodo's sword in Lord of the rings) The edges of you screen start to beat blue warning you so that you don't get attacked by a lone zombie from behind.