Re racks coming with bike so not changing, I get it. If and when looking at front panniers, do note the weights,and waterproof generally are so much more convenient never worrying about wet contents.

re a new bike, ride the thing as much as you can before trip, and this is important, ride it loaded and get the spoke tensions checked a good while before the trip, as they always loosen up a bit with loaded riding, and getting an experienced mechanic to do this will greatly help reduce having any spoke issues during trip.