Welcome to planDisney, Jennifer. I have my own Starwars-obsessed young padawan, so I understand the magic in the experience of building your own Lightsaber.
Right now, as a fellow U.K. resident, I know we cannot book Enchanting Extras such as the
Savi's Workshop - Handbuilt Lightsabers through the Walt Disney World website or over the U.K. Disney phone number. You can try to use the chat function within My Disney Experience App (scroll and open the Chat With Us tab), and a helpful Cast Member may be able to book you a spot in this chat area, subject to availability. Jennifer, if you can't make an advanced booking, please know that a limited number of same-day reservations (up to 2 hours in advance) and walk-ins may be available.
If you don't secure a spot at Savi's Workshop, you can buy a customised Lightsaber at
Tatooine Traders. My little Jedi loved choosing the different components of his saber. The Cast Members were patient and engaging, and it was an ideal price point for a Lightsaber for a younger knight. There are often quieter crowd levels here, and there is no need to prebook.
I have not built a Droid at the Droid Depot but I've perused the shop many times. Again, the same booking restrictions apply to this experience for us U.K. Guests, but I've frequently seen walk-up availability open.
I feel it's part of my Jedi duty to recommend the Felucian Kefta and Hummus Garden Spread from Docking Bay 7 Food and Cargo. You can mobile order here, and eating outside in the crumbling marketplace was one of our treasured memories from our last trip. You'll have so much fun just wandering around the immersive Black Spire Outpost on Batuu, just watch out for the First Order.
May the force be with you, Jennifer. Please let me know if I can help with any other questions ahead of your epic adventure, Louise.