PortalSeattle Network is not a Domain Registrar.  We use and recommend GoDaddy.com.  

Once you've registered your domain name(s), and have pointed them to our Name Servers,
return here to finish setting up your PortalSeattle account.
During the registration process, you will be asked about NAME SERVERS

Use the following if you are hosting your Domains at PortalSeattle:
NS1.PORTALSEATTLE.NET
NS2.PORTALSEATTLE.NET

If you have any questions about this process, feel free to contact for assistance