Load Balancing / Failover cluster

Hi,

We have to develop an application for one of our clients. We are considering using PostgreSQL as the database. However, reliablity and scaliblity are key consideration. So before we go the PostgreSQL way, I would like to be sure that it supports the following features.

1. Load balancing using more that 2 server in active-active mode. It should be transparent to the client application. We should be able to add server as and when needed as growth is still unpredictable.

2. Failover, where one server takes up the load in case of failover of a server in the active-active cluster. Loss of last uncomitted transaction is acceptable but the client application should not have to restablish connection.

Basically we are looking for feature similar to Oracle RAC (Real Application Cluster) with TAF (Transaction Application Failover).

Can somebody tell me if these features are available. If yes, where can I find some reference realted to them (how to configure, relative performance etc).

Regards

Amitabh