For most of my testing, I am using a Raspberry Pi 3B+. It easily handles the load of the honeypot. My current main test system, which covers 5 public IP addresses, uses about 3 GB of disk space on the SD Card, less than 200 MBytes of RAM and the CPU is at about 70% idle. So pretty much any Raspberry Pi will work.
I do recommend that you are using a wired network connection for reliability.
Just to allow for some future growth, I recommend the following hardware configuration:
- Raspberry Pi 3 (or virtual machine)
- 1 GB RAM
- 16 GB SDCard
Monitor/Keyboard is not required, but some find it helpful for configuration.