Once the lubricant is overtaken by water the bearings will rust, no matter what bearings you buy. Some will last a few times some will last longer but then seize up. You can bring them back to life though, especially decent bearings. Just clean with Carb/injector cleaner spray, get them running again and then use bearing lube/speed cream etc to get them rolling properly. The board is the main thing that will die and will be done after one rain session if you’re trying to learn stuff. You could have a wet cruising board for a while before it’s really soggy beyond use.
Truckswise, they should be fine as long as you dry and clean the bolts/axles after every use to stop rusting.