Reverse Auction/ Freelance Script Edits

We are looking for a programmer to help improve a reverse auction script. (1) Attachments: Figure out why they aren't attaching and then fix the problem. (2) Edit listings: Edit listing if there are no bids only. (3) Request Payments: Once account hits zero, request payment before the user is allowed to post. (4) Portfolio: Fix image attachments. They aren't uploading/displaying (5) Add Description: Allow posters to add to their listings after bids have been placed - notifications send to the bidders. Additional Info (6) Payment/Discounts for certain members and a way to manage this. (Such as special members receive no commissions or pay x amount) (7) There is also a project gallery that will need to be installed. Users (from their account) can upload images from completed projects only (or project from which they won the bid). Thumbnail images are randomly displaied on the gallery page, which open is a pop-up to display a larger view. Reliable programmers with proven track record & working examples/demos only -- please. I'm sure -- as it always happens that more work will come your way as I tend to only work with a select few - so if your open to that it a huge plus. I'm only posting this becuase our current programmers are busy doing other projects for us -- so we currently have an opening. Must sign non-disclosure agreement for project as it had not been released yet.