PHP programmer / web developer with HTML DIV, CSS and JQuery

We are developing a members only online marketplace where we have buyers (members) and sellers (partners) for the travel business, we had a programmer coding the system according to our spec where we provide a spec of what we need and general layout of how each page should look and she created the pages and coded the system. We currently have the registration, account activation, login and some product load more or less finished. Our programmer due to personal reasons was no longer able to continue with the project so we are looking for a new person who is professional, efficient and reasonably priced as there is a lot of on going work with this project. The new person has to build a bidding system according to our spec where each partner receives a request, completes a ticket online with their offer and then this is sent to the member privately via email. Once the successful bid is accepted we would need to accept credit card payment, most likely Paypal to begin. The successful person should be able to ensure that the website is fully compatible with different browsers and also with smart phones. Our former programmer has told us that the skills needed are html div, css, jquery and php. What we would like to do is agree what needs to be done with the successful person and agree a fixed price and delivery time for this first launch phase of the project. It is important that the candidate is reasonably flexible to small changes although we do our best not to keep adding new things as we know it's frustrating for programmers! We prefer a person with travel website knowledge as we want to be able to implement xml feeds and be able to work with external channel management companies to feed in live rates and hotel availability however we will consider programmers without specific travel website knowledge. It would also be great if the person has the skills to develop mobile apps for Android, iphone etc but again not essential.