Client Login / Project Management System for Graphic Designer

We need login page for graphic design clients. Each client will have their own username and password that will give them access to a page that is specifically for them. After they login, they see all their projects with a link, they click on it, and they will see thumbnail of their graphic. They'll have an option of viewing it in Hi-Resolution or as a smaller version, and they'll have an option of clicking on a zip file and download everything in a zip file. They'll also have a place to leave a comment. Admin should have a way to upload photos and have low-res versions and thumbnails created automatically. The entire system should be nicely styled and professional looking. With you bid, please tell me what CMS or system you would use to develop this. Pre-existing solutions are welcome. Linux web hosting.