We are looking at deploying two SRX side-by-side, with a T1 external each and VRRP internal. Really because clustering this would not work so well in the absence of ECMP. If we are too cautious and someone has this deployed as a cluster, I'd love to hear about it over in the SRX forum.
We'd like to synchronize certain stanzas of the configuration - security and routing come to mind - between the two using a commit script. Before we go and try to come up with our own version, has someone done this already?
I haven't seen a commit script but the operational script "share-data" (in the library) uses groups to share configuration data across boxes. It works very well. I have a very brief document I put together for one of my customers on how it is used if you wanted it.