Because life is easier when it's simple
There are thousands of haberdashery websites on the internet, so in the spirit of making things simple for all of us, ESPECIALLY those based in the UK here is a list of the ones I have come across on my internet shaped travels.
http://www.candy-cords.com (UK based & very good for friendship bracelets!)
Like I said, this is just a rough guide of a few, the top six I would say are ones i use regularly. the rest are just random browsings.