Changing the zombie models can be done by modifying some of the files, however runners are a different type of npc, meaning they can't be removed as their spawn is hardcoded into the map files.

:(

Don't be sad, games must evolve, if not then the industry would stagnate. What you can request instead is for someone to make a map with walkers only (or make it yourself, it's not very hard and it's an interesting thing to spend time doing).

That will be stupid. Zombies that are fast are those who like hyper. Why adding Zombies only male and wearing suit? That will be depressed.

u didnt play the orignal game which was way better than this crap called brainbread 2

Well, if you actually go back and play the game again (brainbread 1 that is), you'll actually have a pretty rough time. There's a lot of things that are klunky and non player-friendly. I'd say that saying 1 is better than 2 is mostly due to nostalgia and that there weren't many multiplayer zombie games at the time.

BB1 has great maps, and a nice atmosphere, the rest is shait tbh. Porting the original zombie models is possible but you need to re-rig them / skin them onto our zombies rig..