There are a few places that have told me to call back in a month or so and They could see what they could do about a special order with there own suppliers .Rice road in st cathrines(or welland) sounds the most promising.They carried a few tropical varieties last summer but I was to late.
Hardy Tropicals | Rice Road Greenhouses and Garden Centre
I have managed to start a few varieties from seed and I am paying to overwinter them at a greenhouse till they get to a good size to overwinter bareroot.The only bananas I have seen in the london and area are basjoos,ensetes ,sdc's,truly tiny etc.