Minor WordPress plugin PHP customization + CSS styling

I have a WordPress website with a real estate plugin (FireStorm Professional Real Estate Plugin) that has a widgetized search form to search for properties. This search form just outputs the fields I select on the backend, but I can't figure out how to add a city field. I need a coder to add the city field to the form and style the form to look nicer per attached mockup. Form needs to be responsive, overlaid on top of a full width image of a house (provided). 95% of this project should be CSS only, but there may be a small amount of PHP required to add the city field and connect form to plugin database. I have a widget area called FrontPageSearch and the theme [login to view URL] file only outputs it on the home page. Here I have the full width responsive image of a house, and I would like the search form overlayed horizontally near the bottom of the photo. A graphic mockup is provided (attached). It doesn't need to be pixel-perfect identical to the mockup...as long as it looks reasonably close and professionally done, I'm happy. Fields will be dropdowns: City Min. Price Max. Price Bedrooms Baths Property Type (default to House) Small link to Advanced Search page The form needs to be responsive, so on a smaller size screen width, you can hide the background image of the house and make the search form fields 100% width (see [login to view URL] and resize the window to see this effect). OTHER NOTES 1. Please do not just scrape the HTML of the form and style it, because as new real estate listings get added in different cities and zip codes, the form needs to dynamically fill in those locations in the city field. 2. Please document customizations made to plugin files so if the author of the original plugin ever provides an update, I'll be able to make necessary changes to core files. I will probably hire you to do it if this happens. :-) 3. There appears to be a minor bug in the default search widget in the Advanced Search link. It goes to /search/search/ rather than just /search/. Please fix this link.