Take a look at the Gloucestershire Old Spots Pig Breeders Club website for lots of information. You need to think about fencing, continous water supply, feed, shelter, shade in summer, transportation, getting a holding number and herd number, signing up with a livestock vet, whether you'll be able to judge their condition so you don't end up taking a trailer full of lard to the abattoir ..... All that before you start thinking about which breed.