Need help in PGSQL

Hi,
I am doing a project in Database Monitoring tool. I am planning to add
pgsql also. So i need the table details, where i can get details like
Request Rate, Bytes Received Rate, Bytes Send Rate, Open Connections,
Aborted Connections, Aborted Clients, Threads Used, Threads in Cache,
Thread Cache Size, Database Details, Immediate Locks, Locks Wait, Key
Hitrate, Key Buffer Used, Key Buffer Size, Key Buffer Size, Key Buffer
Size, Key Buffer Size, Total Memory, SQL Cache Memory, Lock Memory,
Buffer Hit Ratio, Active Connections, Logins/Min, Cache Used/Min, Latch
Details, Agents Statistics , Transaction Statistics,.

Any help on this would be greatly appreciated. Looking for positive and
quick response from you.

Thanks in Advance,
Baskar.S