Just spoken to DLS regarding the DP 680 kit.
Displacement: 673.8cc
Availability: 8-10 days, plenty in Bologna
Price (kit only): £787.26
Extras: Belts, Gaskets
Total: £831.69
No idea how much labour would be, but if there's enough wanting to do it we could probably get a load done at one go. May also be worth asking Ducati UK if they can supply the kits for a decent price when we're visiting the factory.