well, I can't really help you decide which cooler you want - the names are all I've come across - scythe ninja, arctic freezer pro 7... but I can give you the links to UK based sites that do them...
take a look around: Quiet PC for all sorts of wierd cooling thats damn near silent (apparently...)
Quiet PC UK
and the most diverse of the enthusiasts sites: OverclockersUK... this is where you'll find the hardcore stuff...
OCUK main page
For most stuff, Scan usually works out at about a 5er cheaper... but their customer service, in particular their RMA procedure has been shite in my experience. Good for the mainstream enthusiast stuff (I'd liken it to the UK Newegg)but its OCUK for special, Quietpc for quiet...
Scan Computers
Scan's selection of coolers is pretty rubbish - go for OCUK or quiet...
Have fun!