postgres -- monitor and suggestions

Is there a tool that can monitor my postgresql and recommend
configuration changes based on actual use?

For example, when I run VACUUM ANALYZE it tells me that I should
consider increasing the max_fsm_relations.

After monitoring for a period of time, I would like to know if my shared
buffers are set optimally (for example). Or if I need more RAM in the
machine to run better etc..

Thank you
Sim