How best to approach this user input field?

I am developing a site and have need to have a home page input field similar to that found here: https://moz.com/local and here: https://moz.com/local.

How would I best approach the theme portion of this project? Is there a premium theme that could be adapted or would it be best to have it coded from a PSD? (I've not had good luck with PSDs).

Thanks.