When I try to create the account with the Automated Signup script at nixt.org , everything works as planned, the account is queued, but when it tries to create the account, I get this:
Warning: Supplied argument is not a valid File-Handle resource in...
You can host both nameservers on the same machine. Just add 2 different IP addresses - one for each nameserver, and add the DNS zone like this:
DNS1 IN 10.10.10.10
(where the 10.10.10.10) is the ip for DNS1
and do the same thing for DNS2.