Locks that work

^^Thanks, the Abus is the top of my budget really so if i went Kryptonite it would probably be the evo 4 standard rather than the fahg.

By cover I'm assuming you mean its protection against the weather, as I was leaning towards the Abus from reading reviews but I don't want it rusting up and jamming on my bike leaving it stranded.

Cover = insurance in this case.
I have a Abus Granit and think its just fine, one of the best things about it is how smooth and easy locking and unlocking and stowing the lock are.
Oil the lock occasionally and it wont rust up.

abus Granit in smaller size here http://www.ebay.co.uk/itm/ABUS-GRANIT-X-PLUS-MAX-SECURE-LEVEL-15-BIKE-LOCK-Brand-New-R-R-P-79-/150991169300?pt=UK_SportsLeisure_Cycling_BikeLocks_SR&hash=item2327c66714 for £47 delivered.