Could you indicate a place for me to buy the equipment and which configuration would be ideal for the usb miner?
The miner is a GekkoScience Compac F 200 bis 400 GH/s, it is sold out in germany,
I don't know where to buy it in the USA, in europe it is bitshopper.de.
RaspberryPi 4 is sold out mostly everywhere.
Use a search engine of your choice and try to find it.
I can't give you a source for the equipment.
Sidehack (the developer of the gekkos) may know the places where to buy it, so you could ask this question best in the compac F Thread:
https://bitcointalk.org/index.php?topic=5355470.0