Jeff,
Thanks for the PM yesterday, by the way...
As you notice from the long series of messages the Geek linked to (
http://www.bikeforums.net/showthread...hlight=davinci), I'm a big proponent of the daVinci ICS system. It's the best of all worlds. Steel, Alum, or Ti, 26" or 700c, just take your pick.
As noted, they're not cheap, but well worth it. As mentioned, I wouldn't even consider a non-ICS tandem myself. As also noted, I need to sell mine so I can "upgrade" to a 700c JointVenture that fits me better.
Good luck in your search. Let us know if we can help,
Eurastus.