Wordpress Theme Customisation

I am looking for someone that can take an exiting 'Responsive' Wordpress theme and customise it to a clients requirements.

Candidate must have a proven track record in this type of work and be able to present me with a portfolio of completed jobs.

I am only looking for professional developers that can deliver exactly what is requested and on time. I am looking for someone that can take on projects on a regular basis and must be fluent in verbal & written English.