Client side HTTP Upload software

I need a client-side Windows software that will allow a user select multiple files on his computer and the software will automatically upload through an HTTP POST connection that will be given through a website. When user select file(s) for upload and when start upload this software must connect to my main server and main server will respond with upload URL for the HTTP POST and after that this software can start upload to server (http post) when upload finished server will respond with download url for uploaded file and this software must store/show this file to user.... I thinking to integrate this software with my toolbar, something like on megaupload ([login to view URL] )... On server side I`ll use lighttpd and if enabled mod_uploadprogress lighttpd can show file upload progress and will be good if you can integrate this in this software like in megaupload toolbar, how mod_uploadprogress working you can find on [login to view URL] On start I`ll use this software only in toolbar but will be good if this software can work on right click on file on user PC etc. Project requirements: 1. Source code must be included. If you use any third party libraries, the libraries must be properly licensed for distribution. 2. in software must be logo/text for my site... 3. Software should be graphically attractive, simple to use and LIGHT because on start I`ll distribute it with toolbar... 4. Software must allow a user select multiple files from different locations. This means more than just the standard Open... dialog box. User must be able to add and delete files from the transfer queue. 5. You must have experience in writing this sort of software. Please provide past examples if possible. 6. You must stand behind the software and be available to fix any bugs that may arise. If there are modifications to the software that is needed, I will pay you extra for these changes. However, bugs are your responsibility. This is for start but I thinking to create upload/download manager for my site... Thanks.