I have not flown NW in years and have never flown KL but, as a general caveat, beware of some bulkhead row seats, which "Speedbird092" has recommended to you. For example:
On many UA domestic flights, I have sat in the bulkhead row and UA was smart enough to create an open space at the very bottom of the bulkhead so your feet can slip under there and you can have more legroom (and this was true long before their new "Economy Plus" product was introduced). Not so on AA, however, and on some DL flights I have been on. So just be careful about bulkhead rows...you might find your feet right up against the wall with no place to go. At your height, I suspect you have fairly long legs that would be aching for some room to stretch.