If you can find a neutered boar, that's wonderful. If you plan to get a boar and do the neuter when you get him, bear in mind they need to be separated at least 6 weeks before putting them together so as not to risk a pregnancy. Personally, I've always had pairs of sows and they have been fine together. Due to different ages, we've had to pair up girls a few times and have never had a pair that didn't take (I did try to get a meek pig when I knew I had a queen bee at home, but other than that 'dating' isn't an option where I live so we had to hope for the best and, knock on wood, have never had a pair of girls that weren't happy to have each other rather than being alone.)