Undertake changes to an existing website which has been written in PHP

This website has been written in PHP, it has not been written using any modules. There are changes, ongoing, which need to be undertaken. The website uses a MySql database and has a daily chron job. Currently running on a virtual private server which can be a administered through C PANEL. The person selected to undertake this work would be required to be available to maintain and develop existing and new features. I would prefer to deal with someone in the UK who is easily contactable during normal UK business hours. I am not interested in discussing any options to have the website re-written or converted to any other web format.