I have a set-up running on Amazon cloud with a couple of EC2 Instances running through a load balancer.
It is important that the site has a unique(static) IP or set
You can use a DNS service like DNSMadeeasy that allows "ANAME" records. These act like an A Record but can be pointed at a FQDN or IP. So in this case you can point it to the ELB DNS.
Dave