Just found 2 litre bottles of 7up and Cherry 7up for £1 each in my local Asda. Acording to customer services it's available in most stores. The Cherry 7up isn't the pink colour liquid it used to be it's now clear. In my opinion I think it tastes the same as it does in the cans. Used to be able to get cans of Cherry 7up in the odd corner shop but this is the first time I've ever seen it available in a 2l bottle.
Just checked and it's available online too. Not sure about delivery costs etc as never used Asda for online shopping.