I got a few question about a Windows 2003 Active Directory Structure and DNS.

I got 2 servers in two different city that I want to start a fresh installation of Windows 2003 Server. I'm wondering if my DNS and Active Directory structure are possible?

Case #1

Antionline.com as parent Domains
City1.Antionline.com as child domains
City2.Antionline.com as child domains

Question : Can Antionline.com and City1.Antionline.com domains be on the SAME Server? I'm pretty sure for DNS, it's possible but I'm not sure if a domains tree and a domain can exist on the same server.

My goal to achived in this case :
1) City1 create a parent domain (Antionline.com)
2) City1 use the same server to create a child domaine nam (City1.Antionline.com)
3) City2 created a child domain name (City2.Antionline.com)
4) City2 computer DNS name should be computer.city2.antionline.com
5) City1 computer DNS name should be computer.city1.antionline.com

Case #2

Antionline.com as Domains
City1.Antionline.com as Primary DNS
City2.Antionline.com as Primary DNS

Question : Can Antionline.com and City1.Antionline.com be on the same computer and how to force computer at city1 to have the dns name like computer.city1.antionline.com

My goal to achived in this case :
1) City1 created a domain (Antionline.com)
2) City1 use the same server to create a primary dns (City1.Antionline.com)
3) City2 created a primary dns(City2.Antionline.com)
4) City2 computer DNS name should be computer.city2.antionline.com
5) City1 computer DNS name should be computer.city1.antionline.com

Thank for the answer!