Ask the hatchery how they prepare the fish for pick-up.
If they don't do it the way I described, then you'll need to prepare differently, and like tim k suggests, you may need to address some mobile aeration as well as some temperature control.
Further, if you go with something like a larger cooler, it may help to put some kind of soft barrier against the walls as I've seen many fish with injuries from bumping up against fish tank walls during transport; this was more for mature fish though.
