Welcome to planDisney, Sonia.
I'm always happy to see a fellow Guest from Merseyside. Having recently had the pleasure of bringing my own Padawan to
Star Wars: Galaxy's Edge, I can personally testify that you're in for a magical adventure. A trip to Batuu is such an immersive experience. Your son is going to feel like he's truly in a galaxy far, far away.
I'm sorry that you're having trouble booking
Savi's Workshop, Sonia. "I've got a bad feeling about this." Unfortunately, it looks like it's completely booked up for those two weeks that you're visiting. It's possible that there might be a cancelation closer to your trip. Once you arrive at Walt Disney World Resort, I'd keep checking every day to see if any slots open up.
Having recently returned from a voyage to Batuu, I can tell you that there are a few different places that sell lightsabers. Although it's not the same as building your own at Savi's Workshop, if you visit
Dok-Ondar's Den of Antiquities you'll find a collection of famous lightsabers for purchase. This immersive store also houses a variety of the galaxy's rarest treasures. If you venture outside of Star Wars: Galaxy's Edge, you could also make a trip to
Tatooine Traders. This store features a plethora of rare Star Wars memorabilia. You can even build your own lightsaber (although it's not the same quality lightsaber you can build at Savi's Workshop).
If you'd like another suggestion, Sonia, your son could try building his own custom astromech unit at
Droid Depot. Depending on which way the Force moves him, he'll be able to build either a BB-series unit or an R-series unit. Like Savi's Workshop, this experience is also part of the
Enchanted Extras Collection. I noticed that there are a good number of spots available during your stay. I think your son will love this experience, Sonia. It's also a bit more budget-friendly than Savi's Workshop.
I hope that's helpful, Sonia. As we say in Liverpool, "Have an absolute belter of a holiday."
See ya real soon!
Mike