You are right, Cognos8 can't work whith Cognos10 contentstore but you can skip the Cognos8 part...
This should work:
- ask DB contractor to export-import ContentStore schema from Production to Beta
- install Cognos10 @ Beta, point Cognos10 to the new ContentStore schema
- set up IIS etc for the new Cognos10 @ Beta
Now you should have almost exact duplicate of Production at your Beta environment.
Other option could be
- ask DB contractor for a new schema in Beta database
- install Cognos10 etc
- export-import Cognos Contentstore from Production using Cognos deployment functionality
As for pitfalls and additional work. Difficult to say. These come to mind:
- security: Does your beta use same authentication source (AD, ldap etc) as Production?
If not, do not use database export-import. Start with clean content store, set up security and then migrate data from production using cognos deployment
- you new Beta is a duplicate of production. Do you really want everything from Production?
cleaning, replacing production data sources with beta data sources etc
- In production, do you use scheduled reports delivered via email?
These schedules will be copied to the Beta -> as soon as you fire up Beta, it well start sending emails -> prevent Beta from sending emails, disable unwanted schedules and then enable emails