There are two issues involved.
First of all, you normally want the server software to run all the time, no matter what else is going on on the machine. You have to rely on the person using the computer not to do anything that will cause Panorama Server to quit, or even to click on the software (you can hide the software to make that easier, but it will still appear in the dock). So there is a certain trust level there as to the person operating the computer. If the server is dedicated with no user, that is not a factor.
Assuming you do want a non-dedicated server machine, Panorama Server requires a serial number, and you cannot run two serial numbers on the same computer. So when purchasing, you have to make a special order so that both Panorama and Panorama Server are on the same computer. This is a one time decision, you can’t change your mind later and switch to a dedicated server.
I should point out, of course, that Panorama 6 is rapidly approaching obsolescence. We are working on Panorama X server for release later this year.