I have 6 nodes running on Pi4s because of cheap power consumption, my servers dont actually run storagenodes.
I have one 10TB node that is around 10months old now and only has 2TB of space used and has its own IP, 10TB will take a while to fill up so I wouldn’t go to big but if your solely doing it for fun and you have the space then go for it. Don’t go buying a bunch of hardware for it. Keep in mind that the more nodes on the network the longer it will take to fill the space. If you joined storj when the network was much smaller you would have had a chance to fill a 10TB much faster.
There all on the same internet connection but I have more then one public IPs which I assign it to a different node. Not all have there own IPs only 3 of them do. Im running 3 different networks so they are on there own subnet and there own networks.