For GekkoScience CompacFs with their GekkoScience BaseHub, which is better to use, a RPi 3B+ 1GB, RPi 4B 8GB, or a RPi 5 8GB? Also what do you think of Orange Pi 5 Plus with 16 GB of RAM? Or it does not make any difference to what to what I use?
Use the cheapest, lowest-power device for best efficiency. I've ran all my GekkoScience stuff on a 2B+, no issues whatsoever and pretty low power consumption.