Seeking "Comfort" Tandem

My co-worker is looking for a resonably priced (if possible used, but in good condition) comfort tandem. He has a 15 year old step son, Jake, who is blind and deaf. Jake has had the opportunity to ride a tandem a few times, and loved it.

There is on caveat--Scott is 6'8", and Jake is about 5'9" or 5'10", so it would need to be a larger bike.

If anybody knows of someone who has a used tandem that fits this description, please let me know.

thanks!