Microsoft SBS 2003

I have to build a server for a medical software that needs 2003 server, does not matter what version.

But the office on has 5 systems that will conect to this system.
Can you set up Microsoft Windows Small Business Server 2003 Standard Edition with SP1 5 Clients - OEM to run as a stand alone or do I have to make it a domain controler?

Or am I beter using standard and not small edition?
Just trying to save the user some money.
Any imput would be nice.

For medical purposes, I always use Server 2003 standard, not SBE. I have never run it as a stand alone but I'm sure it is possible. IMO you are better without SBE, you don't need all the extra garbage, and if this is for medical, I'm sure you are aware of HIPAA which is the patient privacy act and electronic data protection of patient data.