Very cool. Tiensvold Farm is a great source for sunflower, pea, and radish seed, but I'm not sure if they ship to the UK. I would definitely give pea shoots a try. They're pretty hardy and they give a good yield. Also I've found that if you keep some weight on top of the suns and peas until they're a couple inches tall you'll get a thicker stem and an overall more uniform, more robust final product.