My recommendation would be the Curve SL. It has 16" wheels. Folds compactly. Is light. I don't know about the 2009 model but the 2008 Curve SL came with the Sturmey Archer 8 speed hub which is excellent and all that you'd need.

If you don't want to spend all that money for the SL then the Curve D3 is a great option too.

The nice think with the Curves from Dahon is that they come with a headtube block that you could fit a Klickfix adapter and attach a backpack to. That would be an elegant solution to your luggage needs.

Of course, looking forward, there is the Dahon Curl lurking in the horizon. Dahon is keeping quiet at the moment but I suspect and hope that folder becomes a game changer. At the very least, it should keep Brompton's designers from sleeping well at night, which is a good thing (tm) per Martha Stewart.