We used the rules from Combat Zone to keep everything easy and it worked very well. The zombie rules are (again) the rules that Pil has written and can be found in the combat zone chronicles.
We used Combat Zone rules. Every survivor was a veteran with ablative/primitive armour (+1 Toughness), other than that they were armed with whatever they had their hands on. All pistols were heavy pistols, models without ranged weapon and models without CC weapons were assumed to have one heavy pistol and one knife (in addition to what they had). Shotguns were counted as auto-shotguns, chainsaws were counted as axes when used single-handedly (Ash) or as an axe and a knife when used with both hands (my chainsaw dude). Guns were rather limited, two models had autoshotguns and I believe one had an SMG (2D8 damage, Short range 20 cm and long range 70 cm, Rate of Fire 3). The zombies were using my "Zombies in the Zone rules":
http://www.combatzonechronicles.net/cozoxa/zomzone.htmWith new zombies appearing on every roll of 1 to hit. There was no zombie player (they just moved to the nearest target) and only zombies within 50cm of a model moved. Also, zombies that couldn't see anything or were in odd places (on top of buildings) didn't move unless provoked in some way.
In the armoury every model could spend a turn to stock up. Stocking up gave a model flak armour (+2 toughness instead of +1), and an assault rifle or combat shotgun. There were also one Machine gun and one Recoilless rifle for whoever got there first.
The game was immensely fun. The two things that made the game extra cool for me were:
1. the size of the table, an 8x4 table really gives you the sense that you can go anywhere you want.
2. the number of players. There were 6 players in the game and all had at least one survivor until the end of the game so there was a lot of interaction going on.