Postgresql Replication Comparison Required

I am doing POC on Posgtresql replication. I am using latest version of
postgresql i.e. 9.1. There are multiple replication solutions avaliable in
the market (PGCluster, Pgpool-II, Slony-I). Postgresql also provide
in-built replication solutions (Streaming replication, Warm Standby and hot
standby). I am confused which solution is best for the financial
application for which I am doing POC. The application will write around 160
million records with row size of 2.5 KB in database. My questions is for
following scenarios which replication solution will be suitable:

If I would require replication for backup purpose only
If I would require to scale the reads
If I would require High Avaliability and Consistency
Also It will be very helpful if you can share the perfomance or experience
with postgresql replication solutions.

Thanks