There's a bit of a scavenger hunt involved in finding the materials you'll need. One day, perhaps, there will be a kit with EXACTLY what you need, and when that happens, you'll definitely find the link here. Until then, I made you some links and lists.
There are several options for finding these. There may be a store near you that has some of the pieces. Your best bet is online, and some good options are sparkfun.com, adafruit.com, amazon.com. Banggood.com and alibaba.com are possible sites too, though it may take longer to get the parts shipped from China.
First option: Purchase a Raspberry Pi, a micro-SD card, and scavenge the rest. Sources are Amazon.com. adafruit.com, sparkfun.com and elsewhere. The current model is 4. The book’s illustrations are of Raspberry Pi 3, and it’s just fine to use this older model; just get one that comes with wifi capability.
These links come from Amazon.com.
Micro SD card, 16gb, preloaded
Micro SD card, 32gb, preloaded
Second option: Purchase a full kit,try something like this, which is more expensive but has all the parts you’ll need:
For these chapters you'll need everything from a string of micro-LED lights, copper tape, coin batteries and conductive thread (Chapter 4) to a breadboard, LEDs, jumper wires and a PIR motion sensor(Chapter 5).
I’ve made us a wishlist on sparkfun.com. Click here to go to it. Choose the individual items you want by clicking "Add to cart" for each one. If you want everything on the list, find the big red button near the bottom that reads: "Add all this stuff to my cart", and click that.
If you'd prefer to use amazon.com, stay tuned, I'm in the process of creating a list there as well.
PS this isn't on the official list, but that virtual Sense-hat from Chapter 5? Here's the real thing.