Custom Magento Theme Development

Hi, I've a PSD design that needs to be converted into fully functional Magento website. There are some custom modifications needed such as when someone tries to access the website, on the load screen it asks for the username, password and access key (which changes every day). So in the back end there should be some sort of field where admin can enter a new key every day. There are 6 main categories (brands) and for each category there are slightly different menu items. In simple words within the category pages, the menu should only display the subcategories of the current category. I'm looking for someone who's professional, reliable, got attention to detail and creates a design which later on can be converted into responsive website. Looking forward to hearing regarding this project. Regards, A