Client Login Area for existing website

Hi I am looking to get a client login area for an existing website, so a simple admin interface so that projects can be added via an admin panel and files uploaded to each project, when the clients login they will be view a list of their projects, when a project is selected the client can preview the photographs and floorplans in jpeg format and next to each image two check boxes, one for web and one for print and at the end of the preview page the client can download the selected images, also a preview page is needed for virtual tours where the client can click a link and a pop up window showing the tour and on the preview page thumbnail of each panoramic image again with a check box beside each image and a download button at the bottom. Extras: -in the admin panel we can add new clients with usernames & passwords. -send an email with the link to the project when completed. -in the user panel the client can also fill out a web order form. -on the contact us page of the website a simple contact us form.