I need some some research on coffee

I'm looking to find a wholesaler for coffee beans for my coffee vending kiosk business which I'm developing. I'd preferably want the supplier to be in the UK because logistically that is easiest for me but if there was a better option elsewhere and shipping wasn't too much then I'd be open to elsewhere.
My requirement is that I don't want to spend more than £15 per kg. But I also want to make sure that they are as good if not better than anything you can get on the high street from Starbucks, Costa etc and this is where I think I could use your help. I don't really know what I'm looking for and how I know what is or isn't good quality without the taste.
Is this something you'd be interested in researching?