Replacing server (SBS2003 / Domain Controller)

I am going to be replacing an older server running SBS2003 that functions as the domain controller and exchange server with a Dell SC430.  Initially I thought that I could build up the new server with the same domain name and settings, and the workstations would log in automatically; however, it didn't work.  After some research, i believe it has to do with different SIDs. 

 

There are 10 users on the network, each who log into the domain on their respective computers and store a lot of information in their domain profiles.  I had contemplated having them join a new domain and merging their profiles, but I'm not sure that is the best solution.

 

Are there any tools to easily migrate from one SBS2003 install to another?  I've seen a few AD migration tools, but I'd love to get some feedback on them.

 

Also, I'd rather not resort to ghosting the configuration over, but would that work?

 

Thanks in advance