Best option for expanding beyond 1 pg server in this situation

Hi,

We have been wanting to HA our pgsql server for some time now. We're
actually reaching the limits of our current server now, so there is a
pressing need to do something to ease the load too.

There are several individual solutions to both of these problems. I
was hoping I could get some advice from someone more experienced
though, about what the simplest most effective way of moving forward
would be? Hopefully I can squash both HA and LB with the same
solution.

So far I've narrowed it down to

Slony-I master/slave replication with failover

or

pgpool-II with heartbeat for failover. The pgpool-II configuration
matrix (http://pgpool.projects.postgresql.org/) isn't terribly clear
(there's no legend) but it leads me to believe failover and load
balancing are mutually exclusive options. Is that so?

About our environment: PostgreSQL 8.3. Over 90% reads. Low data
turnover on all tables involved in most of those reads. High data
turnover on a select few tables. Overall database size is quite small
(1GB).

Any advice/help much appreciated.

Jamie