Any one can comment on a Database matching project

I need to provide a 2 Database solution for
a) a property web site
b) a car web site


Anyone with experience can comment on the project as what are the difficult critical parts?
Also any one wants to quote for this job?

Requirements:
Under 3000 items each
Required searches and list by different criteria
Users have to sign up and log in with password and username
Users can register their properties/cars on offer (Including images)
Users can save searches (or user profiles)
+ A matching process with saved searches and new properties
+ E-mail notification of matches
Credit Card processing

I think of MySQL database and PHP

We will provide the HTML, graphics, hosting, etc..

We are based in London.

Send ideas to URL

Thanks for the comments I have received (off forum) to this project.

It may not happend, but I am posting here the progress of this project

I had a long meeting with the client yesterday and he is now changing the requirements.
Now is only a property site (no car site).
One new requirement is about maintenance; the site will be manage by the client only in terms of adding and removing properties.

We are still working the price and it seams unlikely that we will reach an agreement as he does not want to pay any (significant) hosting and maintenance fees.
He is a bit lost (first IT project in his life)

I am sending a proposal today and the client will decide in about 2 weeks.

Just for your information (please dont spend any time on it) I am I have prepared some definitions and screens in the URL http://www.absite.com/mp/cproca (click in the images and follow links at the bottom of the page)

I will keep you post on what happens.

Regards

Mauricio