I dont think the MSG blocks use Multicast messaging, so the message will be easily routable. Any router will work. You might want to dive into your switches a bit, as most managed switches have routing capabilities. The VLAN definitely wont work, unless you add another ENBT to both racks, which isnt very cost efficient. The ENBTs do not support VLAN tagging, so they would have to run untagged, meaning only one network.
Because this is an industrial environment, I prefer Moxa switches, but any router should work.