I need to be able to allow people to

register a domain name,
set the nameservers for it to point to my server,
direct all domains through to one IP.

I've set up nameservers (ns1.mydomain.com and ns2.mydomain.com) with the A records of each pointing to the IP of mydomain.com (eg. 74.53.196.01)

I've added records in the zone file of mydomain.com -

ns1.mydomain.com IN A 74.53.196.01
ns2.mydomain.com IN A 74.53.196.01

Am I going about this in the correct way?

Any help appreciated