As Happy hippy says pigs can be pets, mine are but they live outside, there are some that take it to the extreme of having them in the house, I'm sure you have seen the programmes on them
The kune kune's are great but I find if you are wanting to clear ground imo then a larger breed would be better, I have had people come and purchase piglets for this reason. Agree that most pig owners want them close at hand, I fret when Alfie my boar goes away to appease various ladies
Yes you will get attached to them they are wonderful intelligent animals who interact very well with people, the other alternative you have is to get a farmer to clear it then get it grass seeded, if it is very stony though you would probably have to stone pick, lifting all the stones and boulders etc off the ground and removing them, might be an easier and quicker way to go, especially since you have spent that much on fencing.
Good luck, Kirsten