Last night I was in historic Frederick Maryland and found a british grocer. I can't remember everything they had, but these are the ones that I do.

Fanta Icy Lemon in 12 oz cans made with real sugar.
Irn-Bru
Tango Apple, Orange and Cherry
Grapefruit Lilt
Ribena

I bought a lamon fanta, and a tango apple -- yum!!