We typically can run about 20k meters per server. So, for 75k meters, they'd need 4 servers.

To protect their data and system uptime (availability), we would like to offer Master/Standby as well, which would mean 8 servers.

I do propose that they buy a 3u SuperMicro micro blade chassis from us, with pnpscada pre-installed. 

It has 12 computers with 8TB SSD each. That would be 8 micro blade servers for the meters, and 4 spare.

If the hardware crashes on one server, the Standby can take over with minimal manual intervention, and almost no downtime.

A system like that would probably cost about R800k, but we'll have to request a quote from our supplier if they want to go that route.