Refining the Idea

I have a general idea for the next Zombie Series I'm writing. Before I put fingers to keyboard (pen to paper) I like taking some time to hash it out.

Right now the next series is tentatively titled "Twisted". Not trying to give too much away but let's say recreational drugs get tainted and lead to a whole lot of undead style shenanigans. The catalyst for the apocalypse is less important to me than picking the core characters I'm going to be writing for the next two years...

They have to be people I can get inside of and relate to so I can tell their story. Characters that breathe and act in the ways that they should. (People do weird things when faced with crazy circumstances).

I'm thinking a recently divorced dad back from being deployed overseas. Goes to stay at his parent's lake house to meet his daughter who his ex is shipping up to him for the summer via train... Not necessarily a special forces dude but more of an average Joe. Maybe a cook but not a Steven Seagal kind of cook...

Other characters we'll meet along the way will be according to where he's at and what pops in my head. Ideas anyone?