You can download the latest Systems Build and Update Utility here (or, yes, by going to support.dell.com, Drivers and Downloads, and choosing your model or entering your Service Tag: support.dell.com/.../download.aspx Just make sure to uncheck the box to install Server Administrator, as it is not on this disk.  The more complete version is found here (SMTD - pay particular attention to the Installation Instructions on the download page of each DVD ISO piece): support.dell.com/.../format.aspx You will need SP2 on your 2003 media to use it with either installation utility.
I am going to do a fresh install of Windows software (Server 2003 R2, 64-bit) on an 1800 server......I have the Dell discs - what softare to I need to begin the wipe/reinstall?  
Reinstall OS on PE1800 server