It may not be a "supported" OS, but it will usually work anyway.  Here are a few more thoughts, in case you're still looking ...
Having issues installing the R2 version of SBS2003 standard server.  It goes through the pre-load OK but when it re-boots to start the Windows install it blue screens with an IRQ_NOT_EQUAL error. The Dell DVD is from December 09 and I have tried one from May 08 but that one just fails to launch. Any ideas ?
PowerEdge T110 & SBS2003 R2