IBM can sell you a LinuxONE machine that's mainframe that runs Linux under the z/VM hypervisor. It's probably the biggest Linux server money can buy. And can be carved out into thousands of really nice average servers. You won't have to worry about network components or latency or unreliable servers or anything like that - you can treat it as a data center in a couple racks.

Another interesting feature is that they are designed to be monitored, because a traditional business model was to lease a mainframe and rent out capacity to smaller companies that'd pay for things like CPU seconds or bytes read/written.