If you're really careful you can drill a hole in a 5 gallon
bucket or 50 gallon drum to put a nipple waterer on. Make the hole so it's a snug fit then screw something on the back side so they can't just pull it out (pigs are rough on things!) I'd think the 50 gallon barrel would be better because they can push over the 5 gallon bucket, so they probably will.
They need a wallow or pool to cool off in when it's warm (mine start to wallow at around 75 degrees), and WILL dump their water to lay in if you don't provide something. I think it's easiest to provide a runway to a central area with the water, wallow, and
shelter so they don't damage too much ground making wallows everywhere, but if you just have those two little ones you can probably just give them a kiddie wading pool for now. They prefer mud in the wallow because they can coat their sides with it and it takes longer to dry off again.