[CentOS] Shearing file systems on the network

I have 4 systems and each one of them has a partition I'd like to be remotely 
accessible on the other 3 systems.

In other words System1 has Partition1. Systems 2,3,4 should be able to 
remotely mount Partition1 from System1. Also System2 has Partition2. Then 
systems 1,3,4 should be able to remotely mount Partition2 from System2 and so 
on.

I tried NFS and it works but only in the ideal world. If one of the systems 
goes down the whole NFS cross-mounting makes the other systems somewhat 
unstable. It's a known issue and I believe you guys are aware of it but I 
just had to see it myself.

What would you recommend? What is the best practice for doing that?

Unfortunately SAN and NAS are not really an option due to some financial 
restructions. I'm thinking SMB...? Would that work?

Thank you
Peter