Hi Tes,
Yes 10.3 is compatible with EEM 12.51 CR04.
Here is the APM Product sub-page containing all the Compatibility Guides:
CA Application Performance Management Compatibility Guides - CA Technologies
In the 10.3 guide please see the "Integrations & Other Extensions" sheet
Currently EEM 12.51 CR04 is not distributed as part of APM 10.3 and at the moment cannot be downloaded from Support Online
Please raise a support case and we will upload a copy of the install software for you. Sorry for the inconvenience!
Thanks
Lynn