External hosting for a DNS server

[Monica Soto Valencia]

Hello everyone, 

I hope someone could help me. I am doing a business continuity plan and I
wonder if there are DNS Servers that would rent space to announce a client's
domain..... 
I am running BIND 9.3.4-P1, I have 1 master and 1 slave but both of them are
in the same network so if the networks falls down  we would be in troubles
that's why I need an option that guarantees the domain's resolution... 
If anyone could help me with possible options I really appreciate it.

Thanks

Regards

Monica S.