I would go for 8i as it would take atleast two more years for the corporations to migrate their existing 8i PROD databases to 9i.

My guess is that, right now, they might go for new 9i databases for any new projects, but for migrating a 8i to 9i, it will take a while.

So, 8i will exist for some time. Also there are lot of materials for 8i.

Then I would go for the 9i upgrade.

All the best

Sam OCP8i