Web Based Project Management Calender

Hello, I'm looking to have a web-based construction scheduling management system built. There should be the ability to, based on permissions, veiw multiple construction projects in progress. There will be several components inside each construction project: Document Storage- ability to upload, download and view PDFs JPGs and other files related to that project. The ability to organize the uploads into different customizable categories or folders. With permissions. Project scheduling calender- similar to google maps. Similar to entering an appointment, be able to enter parts of the job, the time required for that part, details, etc. IE "build foundation, 3 days, ABC foundation builders inc, etc. A drag and move type setup, with permissions. Project management- Basically journal entries for the job to record notes, phone calls, emails, changes, etc. with permissions. I would like to make this available to the customer to view, so it will be pretty, but right now i want to focus on the functionality of it and just use placeholder images for future buttons, graphics, logos, etc. These are the basic nuts and bolts of it, im not sure what the feasible possibilities are, and I dont have a huge budget for this initially- so any additional feature suggestions that could be implemented would be great- IE iphone/android app, reporting tool, update toot, etc. Im not dead set on any particular platform such as Google, Joomla or Squarespace etc, so please make suggestions. Im looking for someone who has done something similar to this before, someone who is easy to communicate with and has some creative input. Please respond with your experience in detail, how you will do the project and how it will work- more than just a one-liner of "lets get started" Keep in mind I am not web programmer savvy so I wont understand the technical stuff. Thanks for your time,