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 model essays in the UK.
They've got over 168,000+ essays, projects, assignments, coursework etc.. all written by GCSE, A Level and Uni students. You get access either by publishing some of your own work, or paying £5.99 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.