Classified site database needed

I need to have someone develop a searchable classified database for selling horses online. It can either by PHP or ASP -- MySQL. I have all the design details together, just need someone to write the program and help me make sure it works. I would like to be able to use FrontPage to make design changes, etc. Site users would need to register and have ability to submit their own ads and pay for them using credit card or paypal. Administrator must have ability to enable or disable ads. Ads must be searchable by state, breed of horse, name from horse pedigree, etc. Date ad was listed must be shown. Users would be notified when ad is about to expire. Ads will contain photos, descriptions and simple pedigree tables listing horse's parents, grandparents, etc. ([login to view URL] is a good example of what I need). Thank you!