It's been a while since you posted and nobody's replied yet...maybe you should check out MarkedbyTeachers.com, TSR's sister site. It has the largest library of essays in the UK.
They've got over 181,000+ coursework, essays, homeworks etc.. all written by GCSE, A Level, University and IB students across all topics. You get access either by publishing some of your own work, or paying £4.99 for a month's access. Both ways give you unlimited access to all of the essays.
All their documents are submitted to Turnitin anti-plagiarism software, so it can't be misused, and the site's used by hundreds of thousands of UK teachers and students.