Replication

I am setting up Linux Virtual Server (LVS). It is a three layer setup.
The first layer is two Virtual Servers, the second layer is 2+ Real
Servers (CentOS 5.3, Apache, freeRADIUS, mail server, etc.) and the
third layer is 3+ PostgreSQL data servers.

Originally, I started out with two PostgreSQL Data Servers (Master &
Slave). Then I realize that I have no failover capabilities. After
searching the internet, I came across two applications, "pgpool-II" &
"PGCluster" which may solve the Redundancy, Replication, Failover &
Parallel processing. Although it is too big of a system but it will be
fun to do it.

Please give me some guidance as to which of these two packages to use?
Keep in mind that I am not an expert but I try hard.

One thing I notice is that PGCluster has a single load balancing server
which manages the PostgreSQL servers. This is a single point pf failure
and that worries me.