I would suggest that all of the above suggestions would be useful, but some may already be produced elsewhere (jerrycans, for instance).
As for with/without hands on weapons, I think you will find opinion split.
WITH hands makes for easy conversion, whereas WITHOUT allows a weapon to be slung or even holstered....choices, choices.
Civilian types without firearms would be a serious bonus too.
I dont think that you can go wrong with dogs of either friend or foe variety.
People will always find uses for them.
Children is an excellent idea.
I am working on a Zombie Survivor project myself (planning/acquiring stage at the moment) and the children are proving the most difficult. I have a few, and am even considering converting some Hobbits, but not many around.
Of course, I have decided to make it more difficult by setting it in the 1920's, so that just compounds my difficulties....

Really looking forward to seeing the rest of your range, and will be taking some off of your hands, without a doubt.