Just playing devil's advocate but is Colchester really the best place for a pack of spotted hyaenas? I can understand the more solitary browns, striped and aardwolves.
A large fenced paddock at West Midlands, Knowsley and Woburn would be a more ideal setup.
I tend to agree with Tetrapod , a large clan of Spotted Hyaena in a safari park setting would look particularly spectacular and probably prove to be a very interesting and active exhibit.( The only slight concern is whether or not they might take an interest in biting car tyres!! )