System advices

Hi list,

I have a question concerning your experiences using PostgreSQL.
We plan to migrate our existing database from mssql to postgresql.
There are 8-12 servers establishing connections for about 30-60
processes each. All queries are of course made at the same time.
We're planning to setup 2 databaseservers in a cluster using failsafe.

My question is are there any experiences or advices for:
1.) Is it possible (I think sure)
2.) How stable is postgresql running with many "clients" (aprox. 600-900)
3.) What hardware do you advice for the servers
4.) Any experiences using postgresql with linux failsafe?

Thanks in advance :)

Hakan