Thanks for the replies, good suggestions but nothing we can use. Using ICMP failover isn't an option because the hosting company has it disabled & they won't enabled it.
The billion just checks to see if the DSL connection is alive.
Brandon, i'm not sure if the Cisco will do what i want it to. PBR is going to route the traffic through the 4G if destined for a particular IP? i can't do this, as it would cost a small fortune in data bandwidth.
I am wanting to know if there is a router that can actually check to see if a website is alive & if not then fail over.