Experienced LAMP Developer Position

I run a number of web sites in the Internet marketing field, built mainly on PHP/MySQL, and sitting on a redhat linux dedicated server at Rackspace. I need someone based in the UK to help maintain and update my sites, on an ongoing basis. The number of hours each week will vary depending on project levels, but ideally I'm looking for someone who has twenty or more hours a week to commit on an ongoing basis, and is available to some extent most days per week. They will use Plesk and SSH to manage the server and the domains, liaise with technical support at my host as necessary, plan and implement updates to the live sites as required, investigate and fix issues as they arise, and possibly assist with the development of new sites. The right applicant should be proficient and highly experienced in LAMP technologies, including server admin, and have good experience of working with business-critical live systems (the core of my business IS one of these web sites, providing an Internet marketing service to hundreds of users, so it needs to be live and operational at all times). Some experience in Perl, Javascript and preferable AJAX is also required. They will also need to be able to maintain and create system documentation for ongoing reference purposes. The right individual will be well-motivated, professional in their approach, and committed to high standards of output. The ability to work well under pressure is required. The intention is for this to be a longer term indefinite assignment for the right candidate. Please only apply if you are based in the UK, other applicants will not be considered. If you are interested, please include your CV, and 2 or 3 references from previous assignments/positions would be preferred. My budget is £20 - £30 per hour. I am looking for an immediate start.