wow. what a great idea. if cost is really no object, I would go for the Bike Friday Air Llama. if you cruise this forum you will find few if any negative comments on bik friday - truly a superior ride. only thing is, it could cost you $3,000 or more.
http://www.bikefriday.com/bikecat99.cfm?cat=3
the Pocket gnu and pocket llama would also be great choices for less $$. if you need to get closer to $500, the dahon's are good, too.