Which Zombie mod do you think would fare better?

I would love to play a zombie mod, either one sounds good. 

For the Countdown style, I think having multiple countdowns could be fun. You would have a certain number of turns before the first 'wave' of zombies, then a break to gather survivors etc. This would let you keep everything on one map instead of having levels.

A more ambitious, but to me more potentially interesting option would be the second style you propose. For the second style, what would be great would be to mod an entire Zombie 'faction' with a very straightforward set of options. The Zombies would research technology using their "brains" resource (taken from civilians), which would be used to upgrade their zombie-armies. Their other resource would be "Zombies", for example when they take a town it would destroy the population but give the zombie player a certain amount of "Zombies" resource, representing converted civilians. 

Since zombie towns would have no survivors, the game would sort of be a race to contain the zombie horde before they get so many towns (and brains!) that you cannot fend them off.

This idea could either be a Total Conversion, or if the game mod tools are good enough could simply be an actual faction to play with or against!

Not sure what kind of scripting would be required to make monsters home in on the human player and move towards his town, so I think the first of your two ideas would be the easiest to implement.

That should just be a starting point, though, to get the ball rolling.

The idea reminds me of the Warcraft 3 campaign in which the undead had poisoned the human's grain and the villagers were turning into zombies.  On one level, I think, you had to stop a caravan from delivering grain.  A mechanic like that could be interesting--zombie faction sends caravans to cities and, if the caravan arrives, the city becomes infected.

If you do this, you could break it up into a bunch of mini-mods, introducing new unit types and structures.

I wonder if you can set structures to spawn monsters.  A graveyard that spawns zombies would be cool.

Also, I wonder if you can set monsters to be friendly towards a given faction.  Zombies that won't attack other (human controlled) zombies would also be cool.

Maybe you could even make it so human players that get conquered by zombies can continue playing--as zombies!  Make it a whole new game mode--last surviving human player wins.

Zombies should have only one movement point.

For changing humans into zombies, you'd probably remove the original unit and spawn a zombie in its place (or replace it with a zombie--if players can continue to play after being defeated).  I wonder, though, if you could change the appearance and stats of the original unit.  Maybe zombification could work like an enchantment, to change the stats.  Since you can change equipment, you should be able to change heads (which seem to work like helmets) and replace normal clothes with tattered zombie clothes; but that would require zombie versions of tons of art assets.  Maybe it's possible to apply decals?  Or you could just create several zombie clothing sets and associate each with multiple original items.  I also wonder if it's possible to change a unit's animation, triggered by an in-game event.  Just changing the original unit's animation to zombie-style movements would go a long way.  Changing the unit's skin and hair colors, also, which hopefully is possible--and easy.

You'd have a lot of work to do on the economy, too.  Farms don't do zombies much good.  Maybe zombies can't train units at all, but have to convert them by killing living units--that way you give them a disadvantage and save yourself work.

Human players should all be Kingdoms.  It doesn't make sense to have evil, death-spreading, human players versus zombies; and it saves you some work in the art department.  Zombies would spread blight like Empires, and they'd essentially be an Empire faction.  (This is another point where a mini-mod could branch off.  An Undead faction could appeal to a lot of people.)

It really is all up to the mod tools, depending on what CAN be done with them will show the type of mods that can follow. If they can make units follow a simple path in warcraft 3 I hope they could give us the tools here also, the modding community would get blown open like WC3.

You'd have a lot of work to do on the economy, too.  Farms don't do zombies much good.  Maybe zombies can't train units at all, but have to convert them by killing living units--that way you give them a disadvantage and save yourself work.

I was thinking more on the lines of zombies being a unit (and not one that can build a town) and when they destroy a town or building they get X amount of zombies from converting the citizens there. X could be many different variables depending on what was destroyed etc. Example = A farm could net 5 zombies... and easy total with no variables.

For changing humans into zombies, you'd probably remove the original unit and spawn a zombie in its place (or replace it with a zombie--if players can continue to play after being defeated). 

This is correct, I would not be changing the unit into a zombie, just spawning a zombie equal to X amount and the original unit would just be dead/destroyed. And yes and undead faction would easily be in the works, but I was just aiming for a simple mod first, then possibly stretch into entire factions etc. This way I would only need to make 1 unit (possibly up to 5-10 if I wanted to make them semi-different) and only need to program them attack things instead of entire city builds etc.

im a fan on zombie mods but i am yet to see this work for a turn based strategy, real times works best with survival horror as far as i know.

zOMG...make all of them! Zombie mods = win!