[CentOS] high availability ideas

Hi,

I'm looking for some recommendations. I need to have some sort of high 
availability for a set of php &  mysql web sites, they must be hosted on 2 
servers, in separate data centres and obviously on differrent IPs.
I can't use a load balancer because that will introduce a single point of 
failure making the "distributed setup" useless. I was thinking some sort of 
drbd/glusterfs/mysql-master-master replication and figure out how to make 
the dns system responsible with the fail over.
Am I going too far with this?

Thanks.