AJAX Developer With Proven Experience

I am designing and building an auction type website. I am familiar with PHP and MySQL but I need certain tasks done on the website without actually refreshing the page. I think this all can be done in AJAX so I am looking for an experienced AJAX programmer with a proven history of work. Basically there will be items up for auction and a live countdown timer will be displayed showing how long until the auction is over. The current highest bidder and bid price will also be displayed. When user123 decides to bid on the item all people watching the auction item will see that there is a new highest bidder and they will see the new bid price. The catch is that anyone watching this item will see the updated information without refreshing the page – everything will be updated automatically and I think this is where the AJAX kicks in. Everything must be in real time. This is the AJAX work that needs to be done: Anything marked with * must be done without refreshing page 1. Registration a. Check entered username against database while on current page and display availability* b. Check that e-mail is valid* (once mouse focus is off the textbox, ensure that it is a valid email) c. Check that passwords are equal* (once focus is off second password box ensure the two passwords entered are equal) d. Ensure terms and conditions checkbox is ticked e. If any conditions are not met – do not allow form submit 2. Login a. Process user login/logout 3. Purchase a. Allow user to select which bid package they want b. Process payment (Paypal/credit card) 4. Main page a. When page is first loaded, sort items based on the auction with least amount of time left b. Display countdown clock c. Show current bid price (update every time a bid is placed)* d. Show most recent bidder (update once a bid is place)* e. Only allow users to bid if they have bids in their account* f. If timer has less than 15 seconds left, when a user bids reset the timer back to 15 seconds.* g. If timer runs out show “Auction Complete”, username of winner, selling price & savings*