MInor Updates on 3D Image Host site

We are looking for a php developer to help us in the following site developments:

1 - We need a new navigation tab link in the header
2 - We need an adpost in the header where a 728x90 gif banner appears for desktop users and 300xx100 banner appears for the mobile and tablet users.
These header spots should appear on all sites not just on the home page. We already have a banner plugin on the site but with different placements
3 - In the footer we would like to add some backlinks - it would be important to be able to update this list manually.

You will have to work on BItbucket, ftp/ssh access is not available for new developers.

We are looking for a long-term cooperation because soon we will have other projects on this site.

If you have any questions just let me know!
Regards
Thomas