Selling Linux to AS/400 Shops?
It would be useful (I think) to focus on how Linux with IBM solutions would compliment their existing AS/400 architecture. It's not generally a great idea to suggest that they scrap their existing applications and move wholesale to another OS or hardware platform.
The bottom line that they'll want to know is if it can save them money while offering an equivalent or (preferable) better service to themselves or their customers.
Focus on integration, scalability, flexibility and IBM's commitment to supporting the Linux arena.