Hi
Do you already have a regulator and just need a needle valve. I got a regulator with needle valve (delivered to uk) from germany from aquaristic.net i've bought stuff from them twice now and had no problems. delivery is a flat rate of about 12 euros up to 36kg. I found that quite a bit of stuff e.g. eheims etc was considerably cheaper than the UK (remember the prices are euros).

some links:
Needle valve: http://www.aquaristic.net/shop/shop....-Dosage-valve/

Regulator with needle valve: http://www.aquaristic.net/shop/shop....-dosage-valve/

Hope this is of some use.

cheers
Neil