If you did a clean install of the SIM server on something newer than Windows 2003 then i would use HP SUM to push the new SPP's if possible. That depends if you accept downtime. If that is a problem at least update the System Management Homepage, wbem/snmp agents and VCA agent. With this package you can at least monitor your servers and use VCA or HP SUM to update your servers.
Also look at the hardware platform you installed SIM on if it's hardware. Depending on the age of your hardware and size of your enviroment you could use newer hardware or run SIM on a virtual server.
If you install a new server and SIM you can export your objects and import them in the new server.
If the old SIM server has trusts with your old servers you can use this trust to set trusts for the new SIM server.