I think you can already have specific banner in each website.
All depend on how you want to acheive this objective.
Which kind of banner do you want to use and customize ?
There are many possibilities:
- You replicate the website and you use the standard joomla banner component. As the data are saved in the DB, you can change its content once the website is replicated.
- You replicate the website and you use a custom module in which you put your banner html code. As the custom module save the banner in the DB, it will be specific to each website.
- You replicate the website and use a specific new kind of custom module that allow the execution of PHP code instead of using HTML as the existing custom module is proposed. This approch has already been used by customers to compute a banner with "dealer" name, address, ... depending on the site ID.
We propose also billable support that you can order at
/download?page=shop.product_details&flypage=flypage.tpl&product_id=35&category_id=1
We can also develop specific extension when requested.