It is obvious that you are not familiar with dns protocols. RFC 2182 3.1 states "that nameserver IPs must be in geographical and topographical dispersed locations". This means that the secondary nameserver IP must be in a different subnet range to the primary IP subnet or in a different geographical location i.e. different country or different state as in the US.
Data Centers in the US and Europe mass produce servers online with disregard to the above RFC, mainly because the TLD domain providers do not insist on this rule, but most country tld registries still require its adherence as does the .ru registry. Another point is that most people who order servers nowadays are trying to break into the hosting field whether for the free or for profit aspect. These people are mostly ignorant about dns protocols.
You can get servers with these requirements relating to the RFC, but it is difficult in the US where your server is housed. If you had of stipulated this requirement when you purchased the server the Data Center may have obliged, but many won't do it because they state that it is not part of their infrastructure. Which is a stupid excuse because it is an easy process with several ways of doing it. Also it is restrictive to what domains you can host.
We have several servers and they are all setup this way with nameserver IPs in different subnets, both in the US and Europe. You just have to search around for the right data center.
To learn more about DNS and the its workings go to
DNSRD there you will find lots of information about DNS and RFC's.