According to some of the Bike Friday folks, the Crusoe frame will shed something like 1.5 pounds; but you have a lower weight limit.

I don't think that you will have any problems with 406 wheels and the gearing. My big chain ring has 50t and the highest gear is 104 gear inches. A 52 or 53 tooth chainring should give you an extra boost if the 104 gear inches is not quite enough.