I generally can tell when the tire is getting too bald (threads, change in colors of tread, flat spot, etc).
But, in your case, you're heading off on a big trip.
I'd probably keep the old tires as spares and start off fresh. Even bring a spare with you if you have space.
I haven't tried all the tires on your list. But, I was impressed by a pair of
Michelin Protek Cross Max Tires.
I never got a flat with them. Good traction, generally paved (wet, dry, even slushy snow).
