A good front-end/UI engineer is in general hard to find, because these individuals ideally need to live at the intersection of development and design. You should also consider searching http://dribbble.com/ for engineers with design/UI interest. Another good destination would be to post a job at http://jobs.37signals.com and make sure you have the right job description. Good front-end guys/girls are usually looking for specific requirements in a job post, to make sure their potential employer is aware of their unique position within the technology stack. Feel free to reach out to me if you wanna know more...