Is it feasible for you to create an additional AMI using Amazon's new EBS backed EC2 instances? There are a couple of reasons to support this. One is that they allow the primary partition to be larger than 10GB (actually up to 1TB), and you can now quickly stop and start EBS backed instances without having to bundle them. We are going to use these exclusively for EC2 instances going forward.
Here is the page that describes the new feature: http://aws.typepad.com/aws/2009/12/new-amazon-ec2-feature-boot-from-elastic-block-store.html
I saw the announcement on this last week, but I've not had a change to look at it yet, it does, initially, seem like the way to go though.
I'll definetly be taking a look for when I do the SR3 ami when it's released.
In the meantime please share any experience you have with this new feature.