Steve, Sorry to hear about you break in, have you noticed anybody previously hanging around that you maybe thought "what do they want" and then thought no more of it, cos these scum tend to "reccy" the place prior to actually breaking in. Also regarding your insurance, if you report it but don't claim because of your £500 excess, it will probably affect your premium next year anyway, Insurance companies being what they are. If you do report it (and I think you are required to) you will probably find yourself up for a review from your insurance company, then they will have you spending your money on their behalf.
Andy, Are you able to give the Police access to your cameras through the internet ? I have spoken to someone before regarding a system like yours and he was saying that you could give the cops access through a password.