As per the title I'm after some recommendations for which supplier is best. Paintman seems to have a good reputation but Paragon is a lot cheaper. (I'm after rattle cans of Keswick green).

Cheers,

Cheaper than both would be your local paint supplier. I have used paintman before but then found a paint store on my local industrial estate that can mix up paint in nearly any form (cans included) from the paint code. far cheaper and the same grade paint as I took the can in from paint man and said I want some more of this!