If you're interested in making a Sympetrum badge, you're going to need two things: blank PCBs to assemble and the parts to assemble them with. Everything you'll need can be easily found on this project's Kitnic page.
Hit the button on the top of the Kitnic page that says "Download Gerbers". You'll get a zip file of the electrical files which describe the circuit board in a way that can be consumed by a fabrication house. There are a wide range of options for tuning these into circuit board you can use. Fab's I've purchased boards from and been happy include PCBWay, Seeed Studio and Dirty PCBs. There are many other options. These boards are designed to fit in the common 100mm x 100mm size which is often heavily discounted. Expect these to cost around $25 (with shipping to the US!) for 10 in any color you want (they were designed for white solder mask / black silkscreen, the design should work correctly in any color).
I love OSHPark and use them for all sorts of projects! Unfortunately for boards this large they are quite a bit more expensive than the Chinese options at around $60 for three boards. The quality will probably be higher but not likely in a meaningful way.
The easiest way to order parts is again to use Kitnic. Below the images of the board there is a quantity selector and a Digikey button. If you press the button the webpage will magically open a Digikey card with all the parts in it (nifty isn't it?). At the time of writing it costs around $13 to build a single board from Digikey
If you'd rather do things the hard way you can directly upload the BOM to Digikey or a tool like Octopart which will make it easy to order from a variety of suppliers.
- APA102C's, (AKA DotStars on Adafruit) may not be in stock on Digikey. If not, you can buy them from Adafruit. You will need 10 for one dragonfly, though I recommend getting extra to fix ones that get damaged during assembly. They are also much cheaper from EBay or Aliexpress, so consider those options if you're comfortable with them or cost sensitive.
- The battery holder may not exactly fit the through holes on the PCB. They were custom sized to fit exactly the cheap holders I got on Aliexpress. You could try lining one leg up and forcing the other to bend. Or use a holder with wires and gluing/taping it into place.
Nothing in this design is particularly sensitive. If some specific part I selected is out of stock it should be safe to replace with a random part with the same parameters.
Sometimes the CPU seems to disappear from the common US suppliers. If this happens and you don't want to source from elsewhere the STM32F051K8T6 can be swapped in place of the normal CPU. It's slightly fancier (AKA more expensive) and will require you to recompile the firmware for it, but that should be it.
To recompile the firmware for this CPU edit the Makefile and swap the CPU variable by commenting out the line for STM32F030x6 and in the one for STM32F051x8.
The final release gerbers are named FF1.1 (formfactor 1.1) are here. This is exactly what the Kitnic link mentioned above links to. This the final design which was used at DEFCON25.
The firmware is "version 4" and is tagged as a release on GitHub (and in the Firmware directory).
If you want to make modifications, all design files made with KiCAD, a "Cross Platform and Open Source Electronics Design Automation Suite." It's very powerful, but has a steep learning curve.