A minimal set of hardware to play with rusEfi consists of
1) stm32f4dicovery brain board - buy it anywhere including Amazon
2) Any USB to TTL/UART adapter, also available on Amazon
3) microUSB cable - you can use an Android phone cable - Amazon
With these three items you would be able to start rusEfi firmware, connect to it with our console java application in order to set stimulation parameters and connect to it with TunerStudio to try online tuning.