Hello Francois, there are usually orchid seeds on the seed lists of the SRGC, Alpine Garden Society, Chiltern Seeds etc. The Hardy Orchid Society may also be able to advise. Although seed of wild plants can be collected in the UK as long as species do not appear on Schedule 8 of the Wildlife and Countryside Act, (with the landowners permission) the collection of wild orchid seed is not encouraged here. Cultivated plants are another matter. Good luck with your search.