PostgreSQL-9.0 Monitoring System to improve performance

Hello Everyone,

I am implementing a PostgreSQL performance monitoring system (to monitor the below) which would help us understand the database behavior -

1. Big Full Table Scans

2. Table with high IOs (hot tables)

3. Highly used Indexes

4. Tables undergoing high DMLs with index scans 0 (with unused indexes)

5. Index usage for heap blk hits

6. Tracking Checkpoints

7. Tracking CPU, IO and memory usage ( by PG processes ) -- desperately needed

8. Buffer cache usage

9. Tables, Indexes and Database growth statistics

and more..

I am struck at building a script or monitoring tool which gets us CPU usage, IO metrics and RAM usage of the database server. 

Can someone please help me achieve this ?

I need to monitor a 12 processor system with 6 cores. I need to know how each CPU is performing.

Please help me know the availability of any open source monitoring tools or scripts for PG-9.0 on RHEL5.

I will hit back with questions regarding monitoring in coming days.

Thanks

VB