We want to create a partner community to allow the partner to access and view cases and reports. However, the boarder expects that when the partner user access the community, he will see the logo of his company instead of our. We have a lot of partners, is this possible through visualforce? Or should we create one community for each partner? Or better to create a website intetgrated with salesforce to allow partner to access and see the reports related to cases and the cases recordo to view/edit?
From the Help:
Maximum Number of Communities Limit
You can have up to 100 communities in your Salesforce org. Active, inactive, and preview communities, including Force.com sites, count against this limit.
To see this limit in your org, from Setup enter Communities in the Quick Find box, then select All Communities. The Maximum number of communities field displays 100.
In essence, you only want to have one community, not one for each of your "partners".
From your description, it doesn't sound to me as though you need a "Partner Community" since you only want to view cases and reports. There are many other less expensive licenses that can do what you want. See Communities User Licenses for a comparison.
As for branding, if your users are all registered users, you can do what you've described using a solution which serves content that's dependent on the
user.accountId property. This can be done via a variety of means the most common of which would be custom CSS but could also be formula based as well using a "Content Management Solution" as with normal web site design (beyond the scope of this forum).