It depends on your use-case. If you're only ever going to be at home then you could put storage on your network and use that. This could be a home/small office NAS on wired ethernet into your router or even a USB hard disk attached to your router (if your router supports it). You could even just designate one of the Macs as the master data store and just allow file sharing between the two.
If you want access to the files when you are away from home then you could use the same sort of set up, preferably with a NAS, but you're going to have to get up a learning curve of how to open your network up for external access. If you buy a NAS then the provider will have almost certainly have a simple-ish way of doing this but......... you're going to have to read up on network security, understand it and be sure your network is secure. I've got a NAS but it sits behind a firewall with no access to the internet in either direction because NAS's and their management web-pages are prime targets for attacks. I don't really want to put the fear of god into you about it, but you should be circumspect. However, all this is doing is creating your own cloud with an amateur network manager, amateur security manager and amateur help desk (they'll all be you, in case you hadn't guessed). I'm not a great fan of iCloud but provided you haven't got terabytes of information the iCloud can provide all the above. There are other cloud providers too which I've got no experience of other than don't use Dropbox. If you go that route then do your research.
Finally - I assume you've got proper backups of all your stuff on separate drives somewhere. Whatever you choose to do, get a backup system in place first. iCloud isn't backup.