If there is a local rose society in your country, you could inquire with them where members may be getting rootstock from (examples: Multiflora, Dr. Huey, Manetti, Fortuniana, De La Grifferaie, Odorata, Rugosa, Laxa, Polmeriana, etc.).
This is a gardening forum for Q&A only and local swaps of plants so finding a local source for the root stock is normally best because there are usually rules imposed on imported plants by government agriculture departments.
Is there any way to search members by origin. I thought there was someone on here from Dubai at 1 point. Perhaps they No where to get such root stock and what the restrictions are for importing in the area.