Hello joc,
If you wish to have more replies to your post I advice that you share some details of your campaign. Custom models take many hours/days to make, and most people I know won't jump to do free models unless they are interested in the idea/project.
Sharing images, ideas, number of models needed and the details needed for every model would help you to attract some modelers interest (not guaranteed of course, but better that just ask people to PM you without more info).
PS: also if you state what you need there is the change that someone has/knows about a model that already fulfills that role, and will share you the link to the model.