Perhaps, how logs are read or processed solely depends on your external log processing tool.
I believe for such kind of monitoring Solution Manager 7.1 itself is sufficient. The old RZ20 is a one stop for monitoring but as a shop for standard methods only.
If you want to pull logs then may be scripts and custom programs on operating system level can do this task.
You should also check with the vendor who is providing this system for integration with SAP or always better raise an incident to check options at your disposal.
Regards