Your height and weight become relevant from this point on, but to transform your bike into a small folded pack (and not miss a trail while messing with it), I suggest 16 inches for the wheels. Since folding it extra-small is not important, I would exclude the Brompton and focus on Bike Friday Tikit and Dahon Curve.

If budget wasn't an issue, I would go with a Tikit. Great, solid bike with fast fold, lots of room for upgrades and longer wheelbase compared to the Dahon.