Pistar is at version 4.x now. This is software the runs on a Raspberry Pi. Pi 3 model B has plenty of power to run PiStar. You could run it with a Pi 4. Main problem with the Pi 4 is finding a nice case the fits both the Pi and the mmdvm modem.
Add a mmdvm modem, SD card, to the Pi and you have pretty much all you need. You probably have a micro USB power supply laying around. If it can output 1 amp or more that should be OK for a Pi 3B.
Pi 3B is wired or wifi.
Gigaparts sells a complete hotspot.
I have more than I need, if you are interested in a used one, that happens to be fully configured send me a pm.