My hardware is an evolving situation, but I currently have 5 mini PCs, with various used hardware.
3 have 2TB disks, 2 have about 250GB disks.
Each box is set to have a max of 100 nodes, but they adjust down depending on CPU load, memory usage and available storage.
I allocate about 15mbit outbound bandwidth per box and unlimited download bandwidth (about 3x of outbound, currently).
Port forwarding is used to direct traffic to the right box.
Currently, this results in about 225 nodes in total.