AS400 Infrastructure Monitoring Setup Consultation

I'm seeking an expert to guide me on setting up the right monitoring systems for my IBM AIX (AS400) infrastructure. The goal is to be able to monitor system performance, security events, and application logs in real time. The deliverable for this initial phase is a comprehensive documentation detailing the setup process and considerations. Currently, I'm familiar with and using Nagios, but I'm open to recommendations for other tools or systems that may be more effective.