I hate to say this but could you please go into a bit more detail?
What specifically do you require? Will these be paid for or would these be based on donations? If donation based, then why? When you say machines do you mean the physical system or just a VPS Container? etc.
Site A = http://22.214.171.124/ (valid working demo), when you goto 126.96.36.199, its actually routing though a couple machines before you reach your destination, if one of the responders (via ping for a domain) gets attacked, the route is shutdown, but 188.8.131.52 remains online.
Why? This is because we route it though multiple machines before it reaches its destination, so if SERVER C goes down, lets say SERVER B kicks in, so attackers would have to find 100's of ips and launch attacks at every single ip, which is almost impossible.