Customiza Search Function of a Wordpress Template

We need a developer who customizes following Wordpress template: [login to view URL] details of the theme here: [login to view URL] We would like to change the search function. Instead of dropdown for cities which is default, we would like that user can type a city or some cities there for which he's searching an apartment. There are also some changes to be done in SQL-Database for the idea which we have. After your bid and if we think we could imagine working with you, we will contact you and send you the document with exact instructions what is to be done. You still can change your bid then if you think that it's more complicate that you thought but let's discuss it.