Petra's Tech Shop
They can ship to the UK if you call them.
UK Based Stores
1. Over-Clock UK - premier watercooling place in the UK. Home to thermochill
2. The Cooling Shop - Large selection of asetek parts and black ice radiators
3. CoolerCases - full selection of American waterblocks from danger den, D5, DDC, Thermochill, HW Labs
4. WaterCooling Shop - Incredible selection of components from the US, UK and Europe.
5. C&C Central LTD - They stock DD and EK waterblocks as well as selling alpha cool and thermochill rads (if you have any info on their quality of service PM me)
6. Aqua-PC's - They are a new store who are Aqua-Computer's UK distributor, ship internationally, and cary their own watercooling line called "Flow". They also cary EK products and a wide variety of American watercooling products.
7. Chilled PC - They have a wide selection of popular watercooling products for good prices. They ship internationally and users in the EU have reported fast shipping times.