Postgres High Availablity Solution needed for hot-standby and load balancing

Hi

our customer has got the following requirements:

Req1) Master master replication supported, not only master / slave
replication with only the master being writable. If you do have multiple
slave systems they are only useful from a backup and standby
perspective.  Our Application must have a db-connection it can write to.

Req2) Replication of schema should also be possible, not only data 

Req3) Not only a hot-standby-solution is needed. Load Balancing is
wanted for the future.


Currently I am looking at EnterpriseDB but it seems that they dont
support multiple master-replication

best regards
Ragnar