How much reliability is he willing to pay for? Does he need to be up 6 nines? (99.9999% of the time)
How about maintenance accessability?
How about heating and or cooling requirements?
Did he also include the network, communications, and remote data sources?
How is he going to load test the generator?
Are the 20 Amp bundles 120 or 240 Volts?
My first suggestion is to go with dual power sources for each machine. Feed one side from the House panel and feed the other side from a LARGE centralized UPS with a suitably sized transfer switch and generator. Feed the Normal source of the transfer switch with a separate dedicated feed from the house panel.
