With some insurance companies they’ll ask for a ‘Sold Secure Gold’ cycle lock and chain which means it can stand a 5 minute attack.
I got a PJB Bull Point Anchor and an Oxford HD 2.0m chain & lock.
The anchor point is actually a motor cycle gold standard and the chain is long enough for me to loop round the two bikes I own.
Best price was here: http://saundersonsecurity.co.uk/acatalog/Oxford_HD_Chain_and_Lock.html
Loads cheaper than anywhere else and you won’t be disappointed. Just don’t expect to be able to carry the chain around with you in your Camelbac
Don’t confuse motorbike sold secure gold with cycle, other wise you’ll end up spending too much. Soldsecure has it’s own guide: http://www.soldsecure.com/search