I currently have 4 nodes. 1 is a RPI4 4GB, the others are 8GB. The 4GB one is running MyNodeBTC and the others running Raspibolt. Most also running Nodeyez on top. Two of the nodes have UPS as does all the networking gear for stability.
This month I will be building a new node using refurbished Dell Optiplex for stability, performance and expandibility. Will migrate key economic functions to it. Some pi nodes will be converted to pruned nodes so I dont have to upgrade their drives this year or next (they all have 1TB SSD). Others will be decommissioned and probably repurposed into another project.