cattle panels alone won't work. Pigs put their nose under things and lift it up, no matter what size they are.
If you've read any of my recent pig-related posts you know I'm not a fan of kunes, also keep in mind they are very slow growing. I am afraid I have to keep my Kune over winter simply because he is way to small right now.
I would advice you to take two or three strands of electric fence. Pigs highly respect the spark and are perhaps the easiest animals to keep in. They will touch it once, some twice and won't ever go near the wire again. They are really smart and easy to move if you get them used to it.

Move the pig paddock two or three times the first week you get them and they'll know to follow the wire wherever it is. Right now I have this new six months old mangalica pig and he is NOT trained to move, it took us nearly two hours to get him through the gate while our kune went back and forth from the old paddock to the new area three times already. Once he stepped into the new area he immidiately started to follow the wire, I think he gets it now.

One more think about electric. I don't like netting, I have seen pigs getting their eartag stuck and getting entangled in it. Horrible. I never use electrified netting, not even for the goats (I keep goats in with three wires, four if there are baby goats)

As for the size of the enclosure. Is your third of an acre pasture? or woods, or leftover veggie garden? are you going to feed all the excess garden greens and weeds too? It really depends on what you want with them. If you have old milk even better!

I would recommend getting two pigs but would choose a (preferrably hardy )meat breed. These pigs grow way faster so it is easier to feed them to "freezercamp ready" within the growing season. Unless you want to spend a LOT of money on feed during winter. It's amazing how much 8 month old pigs can eat in a day.

Does that answer some of your questions?