Congrats in advance! For something like that you definitely need an actual florist, not just any random shop. I used MashaFlower https://mashaflower.com/en/catalog/bukety for my wedding proposal two years ago and they nailed it. Their florists made a custom arrangement based on what I described — I told them the vibe I wanted and they put together a bouquet and several smaller compositions for the villa. MashaFlower handled delivery during the day while she and I were out at the beach, so when we came back everything was already set up. They’re used to weddings and photo shoots so they understand the pressure of timing. Send them a message in advance, describe what you want in detail, and ask to coordinate delivery time carefully. She said yes, by the way.