Reaction backpack by Kenneth Cole has four lockable pouches. Laptop pouch is well padded. The sleeve on the sides is too short for a full size water bottle.
The end of the zippers have a hole to lock a luggage padlock on. I don't think Medeco manufacturers luggage padlocks.
Abloy manufacturers high security luggage padlocks but they are not rekeyable. Local locksmiths do not have Abloy blanks to make more keys.
I purchased these combination luggage padlocks: