Systems Management software for SMS Distribution Servers

We use 15 SMS 2003w/SP3 Distribution Servers, that, due to the requirements, are just Optiplex Desktops (GX-270/620/755) with 4 GB RAM and 160 GB HD's, running Server 2003 Ent R2 w/SP2.

Since they are not actual server models, Server Administrator won't load, but, since they aren't running XP, OMCI won't load.

Any way to put monitoring software on these computers, to report back to ITA or Altiris (freebie version)?