What are some common DR configurations for grid control?

RAC is out of the question - no budget for it.

We currently are running our primary dataguard (DG) databases out of our 'East' GC server and our standby databases out of our 'West' GC.  The idea is that if we fail over to the 'West' we already have a working grid  to manage these databases.

It is my understanding that we would benefit from having both the primary and the standby databases running from the same Grid.  I know that managing jobs and job libraries would be simplified.

I want to propose having all the databases controlled by on GC system with a DR GC waiting to take over in the case of a catastrophic failure at the primary site.  I know we can replicate the grid repository using dataguard but what are the requirements for the web services part.  (I found an GC 11 doc that touched on this but nothing for 12G).